all-out

UK: /ˌɔːlˈaʊt/ US: (ôl′out′)

WordReference Random House Learner's Dictionary of American English © 2025

ˈall-ˌout,  adj. [before a noun]

1. using all one's resources;
   complete;
   total:
   an all-out effort.

WordReference Random House Unabridged Dictionary of American English © 2025

all-out  (ôl′out′), adj. 

1. using all one's resources;
   complete;
   total:
   an all-out effort.

• adjective, adjectival use of all out utterly, completely, Middle English al out 1905–10

Synonyms

unstinting, exhaustive, unremitting.

Collins Concise English Dictionary © HarperCollins Publishers::

all-out adjective

1. using one's maximum powers: an all-out effort

adverb all out

1. to one's maximum effort or capacity: he went all out on the home stretch