[ preposition in-sahyd, in-sahyd; adverb in-sahyd; noun in-sahyd; adjective in-sahyd, in-, in-sahyd ]
See synonyms for: insideinsides on

  1. on the inner side or part of; within: inside the circle;inside the envelope.

  2. prior to the elapse of; within: He promised to arrive inside an hour.

  1. in or into the inner part: Please go inside.

  2. indoors: They play inside on rainy days.

  1. within one's heart, reason, etc.; by true nature; fundamentally: I know inside that he's not guilty.Inside, she's really very shy.

  2. Slang. in prison.

  1. the inner or internal part; interior: the inside of the house.

  2. the inner side or surface: the inside of the hand;He pinned the money to the inside of his jacket.

  1. a select or inner circle of power, prestige, etc.: a man on the inside.

  2. the shortest of several parallel, curving tracks or lanes; the part of an oval track closest to the inner rail: The horse came up fast on the inside.

  3. the inward nature, mind, feelings, etc.

  4. Slang. confidential or secret information.

  5. an inside passenger or place in a coach, carriage, etc.

  1. situated or being on or in the inside; interior; internal: an inside seat.

  2. acting, employed, done, or originating within a building or place: He used to work on the dock but now he has an inside job.

  1. derived from the inner circle of those concerned in and having private knowledge of a situation: inside information.

  2. Baseball. (of a pitched ball) passing between home plate and the batter: The pitch was low and inside.

Idioms about inside

  1. inside of, Informal. within the space or period of: Our car broke down again inside of a mile.

  2. inside out,

    • with the inner side reversed to face the outside.

    • thoroughly: completely: She knew the work inside out.

Origin of inside

First recorded in 1350–1400; Middle English; see origin at in, side1

synonym study For inside

7. Inside, interior both refer to the inner part or space within something. Inside is a common word, and is used with reference to things of any size, small or large: the inside of a pocket. Interior, somewhat more formal, denotes the inner part or the space or regions within; it usually suggests considerable size or extent, and sometimes a richness of decoration: the interior of a country, of the earth, of a cathedral.

Opposites for inside

Words Nearby inside Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use inside in a sentence

British Dictionary definitions for inside


  1. the interior; inner or enclosed part or surface

  2. the side of a path away from the road or adjacent to a wall

  1. (also plural) informal the internal organs of the body, esp the stomach and bowels

  2. inside of in a period of time less than; within

  3. inside out with the inside facing outwards

  4. know something inside out to know something thoroughly or perfectly

  1. in or to the interior of; within or to within; on the inside of

  1. on or of an interior; on the inside: an inside door

  2. (prenominal) arranged or provided by someone within an organization or building, esp illicitly: the raid was an inside job; inside information

  1. within or to within a thing or place; indoors

  2. by nature; fundamentally: inside, he's a good chap

  1. slang in or into prison


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

Other Idioms and Phrases with inside


In addition to the idioms beginning with inside

  • inside of
  • inside out
  • inside track, the

also see:

  • on the inside
  • step in (inside)

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