adjective, sound·er, sound·est.


deeply; thoroughly: sound asleep.

Origin of sound

1150–1200; Middle English sund, Old English gesund (see y-); cognate with Dutch gezond, German gesund
Related formssound·ly, adverbsound·ness, noun

Synonyms for sound Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for soundly

Contemporary Examples of soundly

  • Cuomo ran for governor in 2002, but pulled out before he was to be soundly defeated in the Democratic primary by Carl McCall.

    The Daily Beast logo
    Andrew Cuomo Ignores Rural New York

    David Fontana

    November 8, 2014

  • If they followed the views of the local residents, the mosque would be soundly defeated.

    The Daily Beast logo
    When Bigotry Comes to Your Hometown

    Dean Obeidallah

    July 11, 2014

  • Even those who simply wished to reform the rabbinate lost out, as the dovish candidate, Rabbi David Stav, was soundly defeated.

  • In the presidential race of 2007, Socialist Ségolène Royal was soundly beaten by Sarkozy, 53 percent to 47 percent.

    The Daily Beast logo
    France's Socialist Comeback?

    Tracy McNicoll

    October 10, 2011

  • When Santorum stood for election to a third term in Pennsylvania, the voters, including a number in the GOP, soundly rejected him.

    The Daily Beast logo
    Rick Santorum Needs a Miracle

    Matt Latimer

    June 7, 2011

Historical Examples of soundly

  • Making sure that all were soundly sleeping, he stole quietly out.

  • The child was sleeping so soundly it seemed impossible that he could wake for some time.

  • "You see how soundly she is sleeping," resumed the unhappy mother.

  • And presently Jan was sleeping almost as soundly as her obstreperous niece.

    Jan and Her Job

    L. Allen Harker

  • Then at night she sleeps so soundly that she never wakes up to ask me if I'm in pain.


    Emile Zola

British Dictionary definitions for soundly




  1. a periodic disturbance in the pressure or density of a fluid or in the elastic strain of a solid, produced by a vibrating object. It has a velocity in air at sea level at 0°C of 331 metres per second (741 miles per hour) and travels as longitudinal waves
  2. (as modifier)a sound wave
(modifier) of or relating to radio as distinguished from televisionsound broadcasting; sound radio
the sensation produced by such a periodic disturbance in the organs of hearing
anything that can be heard
a particular instance, quality, or type of soundthe sound of running water
volume or quality of sounda radio with poor sound
the area or distance over which something can be heardto be born within the sound of Big Ben
the impression or implication of somethingI don't like the sound of that
phonetics the auditory effect produced by a specific articulation or set of related articulations
(often plural) slang music, esp rock, jazz, or pop


to cause (something, such as an instrument) to make a sound or (of an instrument, etc) to emit a sound
to announce or be announced by a soundto sound the alarm
(intr) (of a sound) to be heard
(intr) to resonate with a certain quality or intensityto sound loud
(copula) to give the impression of being as specified when read, heard, etcto sound reasonable
(tr) to pronounce distinctly or audiblyto sound one's consonants
(intr usually foll by in) law to have the essential quality or nature (of)an action sounding in damages
See also sound off
Derived Formssoundable, adjective

Word Origin for sound

C13: from Old French soner to make a sound, from Latin sonāre, from sonus a sound




free from damage, injury, decay, etc
firm; solid; substantiala sound basis
financially safe or stablea sound investment
showing good judgment or reasoning; sensible; wisesound advice
valid, logical, or justifiablea sound argument
holding approved beliefs; ethically correct; upright; honest
(of sleep) deep; peaceful; unbroken
thorough; completea sound examination
British informal excellent
law (of a title, etc) free from defect; legally valid
constituting a valid and justifiable application of correct principles; orthodoxsound theology
  1. (of a deductive argument) valid
  2. (of an inductive argument) according with whatever principles ensure the high probability of the truth of the conclusion given the truth of the premises
  3. another word for consistent (def. 5b)


soundly; deeply: now archaic except when applied to sleep
Derived Formssoundly, adverbsoundness, noun

Word Origin for sound

Old English sund; related to Old Saxon gisund, Old High German gisunt




to measure the depth of (a well, the sea, etc) by lowering a plumb line, by sonar, etc
to seek to discover (someone's views, etc), as by questioning
(intr) (of a whale, etc) to dive downwards swiftly and deeply
  1. to probe or explore (a bodily cavity or passage) by means of a sound
  2. to examine (a patient) by means of percussion and auscultation


med an instrument for insertion into a bodily cavity or passage to dilate strictures, dislodge foreign material, etc
See also sound out

Word Origin for sound

C14: from Old French sonder, from sonde sounding line, probably of Germanic origin; related to Old English sundgyrd sounding pole, Old Norse sund strait, sound 4; see swim




a relatively narrow channel between two larger areas of sea or between an island and the mainland
an inlet or deep bay of the sea
the air bladder of a fish

Word Origin for sound

Old English sund swimming, narrow sea; related to Middle Low German sunt strait; see sound ³



the Sound a strait between SW Sweden and Zealand (Denmark), linking the Kattegat with the Baltic: busy shipping lane; spanned by a bridge in 2000. Length of the strait: 113 km (70 miles). Narrowest point: 5 km (3 miles)Danish name: Øresund Swedish name: Öresund
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for soundly

c.1400, "safely;" also "deeply" (of sleep), from sound (adj.) + -ly (2). From 1570s as "thoroughly."



"noise, what is heard, sensation produced through the ear," late 13c., soun, from Old French son "sound, musical note, voice," from Latin sonus "sound, a noise," from PIE *swon-o-, from root *swen- "to sound" (cf. Sanskrit svanati "it sounds," svanah "sound, tone;" Latin sonare "to sound;" Old Irish senim "the playing of an instrument;" Old English geswin "music, song," swinsian "to sing;" Old Norse svanr, Old English swan "swan," properly "the sounding bird").

The terminal -d was established c.1350-1550 as part of a tendency to add -d- after -n-. First record of sound barrier is from 1939. Sound check is from 1977; sound effects is 1909, originally live accompaniments to silent films.

The experts of Victor ... will ... arrange for the synchronized orchestration and sound effects for this picture, in which airplane battles will have an important part. ["Exhibitor's Herald & Moving Picture World," April 28, 1928]



"free from special defect or injury," c.1200, from Old English gesund "sound, safe, having the organs and faculties complete and in perfect action," from Proto-Germanic *sunda-, from Germanic root *swen-to- "healthy, strong" (cf. Old Saxon gisund, Old Frisian sund, Dutch gezond, Old High German gisunt, German gesund "healthy," as in the post-sneezing interjection gesundheit; also Old English swið "strong," Gothic swinþs "strong," German geschwind "fast, quick"), with connections in Indo-Iranian and Balto-Slavic. Meaning "right, correct, free from error" is from mid-15c. Meaning "financially solid or safe" is attested from c.1600; of sleep, "undisturbed," from 1540s. Sense of "holding accepted opinions" is from 1520s.



"fathom, probe, measure the depth of," mid-14c. (implied in sounding), from Old French sonder, from sonde "sounding line," perhaps from the same Germanic source that yielded Old English sund "water, sea" (see sound (n.2)). Barnhart dismisses the old theory that it is from Latin subundare. Figurative use from 1570s.



"narrow channel of water," c.1300, from Old Norse sund "a strait, swimming," or from cognate Old English sund "act of swimming, stretch of water one can swim across, a strait of the sea," both from Proto-Germanic *sundam-, from *swum-to-, suffixed form of Germanic root *swem- "to move, stir, swim" (see swim (v.)).



early 13c., sounen "to be audible, produce vibrations affecting the ear," from Old French soner (Modern French sonner) and directly from Latin sonare "to sound" (see sonata). From late 14c. as "cause something (an instrument, etc.) to produce sound." Related: Sounded; sounding.

Online Etymology Dictionary, © 2010 Douglas Harper

soundly in Science



A type of longitudinal wave that originates as the vibration of a medium (such as a person's vocal cords or a guitar string) and travels through gases, liquids, and elastic solids as variations of pressure and density. The loudness of a sound perceived by the ear depends on the amplitude of the sound wave and is measured in decibels, while its pitch depends on its frequency, measured in hertz.
The sensation produced in the organs of hearing by waves of this type. See Note at ultrasound.



A long, wide inlet of the ocean, often parallel to the coast. Long Island Sound, between Long Island and the coast of New England, is an example.
A long body of water, wider than a strait, that connects larger bodies of water.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Idioms and Phrases with soundly


In addition to the idioms beginning with sound

  • sound as a bell
  • sound bite
  • sound off
  • sound out

also see:

  • safe and sound
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.