Dictionary.com

mast

1
[ mast, mahst ]
/ mæst, mɑst /
Save This Word!

noun

Nautical.
  1. a spar or structure rising above the hull and upper portions of a ship or boat to hold sails, spars, rigging, booms, signals, etc., at some point on the fore-and-aft line, as a foremast or mainmast.
  2. any of a number of individual spars composing such a structure, as a topmast supported on trestletrees at the head of a lower mast.
  3. any of various portions of a single spar that are beside particular sails, as a top-gallant mast and royal mast formed as a single spar.
Also called pillar. the upright support of a jib crane.
any upright pole, as a support for an aerial, a post in certain cranes, etc.

verb (used with object)

to provide with a mast or masts.

QUIZZES

QUIZ YOURSELF ON PARENTHESES AND BRACKETS APLENTY!

Set some time apart to test your bracket symbol knowledge, and see if you can keep your parentheses, squares, curlies, and angles all straight!
Question 1 of 7
Let’s start with some etymology: What are the origins of the typographical word “bracket”?

Idioms for mast

    before the mast, Nautical. as an unlicensed sailor: He served several years before the mast.

Origin of mast

1
before 900; Middle English; Old English mæst; cognate with German Mast; akin to Latin mālus pole

OTHER WORDS FROM mast

mastless, adjectivemastlike, adjectiveun·der·mast·ed, adjective

Definition for mast (2 of 3)

mast2
[ mast, mahst ]
/ mæst, mɑst /

noun

the fruit of the oak and beech or other forest trees, used as food for hogs and other animals.

Origin of mast

2
before 900; Middle English; Old English mæst; cognate with German Mast; akin to meat

Definition for mast (3 of 3)

mast-

variant of masto- before a vowel: mastectomy.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

WORDS THAT USE MAST-

What does mast- mean?

Mast- is a combining form used like a prefix meaning “breast.” It is often used in medical terms, especially in anatomy and pathology.

Mast- comes from the Greek mastós, meaning “breast.” The Latin-based analog to masto- is mammo-, from mamma, meaning “breast.”

Mast- is a variant of masto-, which loses its -o– when combined with words or word elements beginning with vowels.

Want to know more? Read our Words That Use masto- article.

Examples of mast-

You may be familiar with the medical term mastectomy, “the operation of removing all or part of the breast or mamma.” The first part of the word, mast- means “breast,” as we’ve seen.  The second part of the word, -ectomy, is a combining form meaning “excision.” Mastectomy literally translates to “breast removal.”

What are some words that use or are related to the combining form mast-?

What are some other forms that mast- may be commonly confused with?

The mast on a ship is unrelated to the combining form mast-, as are a number of other words that begin with the letters mast-, such as masticate. Chew over the origin of this word at our entry for it.

Also note that mast cells, from the German Mast (“fattening of animals for slaughter”), are not related to masto-. These cells give their name to such conditions as mastocytosis.

Break it down!

The combining form algia means “pain.” What is mastalgia?

Example sentences from the Web for mast

British Dictionary definitions for mast (1 of 3)

mast1
/ (mɑːst) /

noun

nautical any vertical spar for supporting sails, rigging, flags, etc, above the deck of a vessel or any components of such a composite spar
any sturdy upright pole used as a support
Also called: captain's mast nautical a hearing conducted by the captain of a vessel into minor offences of the crew
before the mast nautical as an apprentice seaman

verb

(tr) nautical to equip with a mast or masts

Derived forms of mast

mastless, adjectivemastlike, adjective

Word Origin for mast

Old English mæst; related to Middle Dutch mast and Latin mālus pole

British Dictionary definitions for mast (2 of 3)

mast2
/ (mɑːst) /

noun

the fruit of forest trees, such as beech, oak, etc, used as food for pigs

Word Origin for mast

Old English mæst; related to Old High German mast food, and perhaps to meat

British Dictionary definitions for mast (3 of 3)

mast-

combining form

a variant of masto-
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

Medical definitions for mast

mast-

pref.

Variant ofmasto-
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Idioms and Phrases with mast

mast

see at half-mast.

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