utmost

UK: /ˈʌtməʊst/

US: /ˈʌtˌmoʊst/

US: (ut′mōst′ or, esp. Brit., -məst)

WordReference Random House Learner's Dictionary of American English © 2026

ut•most /ˈʌtˌmoʊst/   adj. 

1. of the greatest or highest degree, quantity, etc.:
   of the utmost importance.

n. [uncountable* often: the + ~]

2. the greatest degree or amount:
   provided the utmost in comfort.
3. the best of one's abilities, powers, etc.:
   He did his utmost to win.
4. the extreme limit:
   My patience has been tried to the utmost.

WordReference Random House Unabridged Dictionary of American English © 2026

ut•most  (ut′mōst′ or, esp. Brit., -məst), adj. 

1. of the greatest or highest degree, quantity, or the like;
   greatest:
   of the utmost importance.
2. being at the farthest point or extremity;
   farthest:
   the utmost reef of the island.

n. 

3. Also, uttermost. the greatest degree or amount:
   the utmost that can be said; The hotel provides the utmost in comfort.
4. the most or best of one's abilities, powers, etc.:
   He did his utmost to finish on time.
5. the extreme limit or extent:
   His patience was taxed to the utmost.

• Middle English utmest, Old English ūtemest. See out, -most bef. 900

Synonyms

• 1. maximum, highest, foremost, chief, major.

Collins Concise English Dictionary © HarperCollins Publishers::

utmost / ˈʌtˌməʊst/, uttermost adjective (prenominal)

1. of the greatest possible degree or amount: the utmost degree
2. at the furthest limit: the utmost town on the peninsula

noun

1. the greatest possible degree, extent, or amount: he tried his utmost

Etymology: Old English ūtemest, from ūte out + -mest most