say it: UHT-mohst
utmost is an adjective and noun meaning "of the greatest possible degree or extent or intensity". It carries 4 recorded senses.
highest in extent or degree
“to the last measure of human endurance”
“whether they were accomplices in the last degree or a lesser one was...to be determined individually”
(comparatives of `far') most remote in space or time or order
“had traveled to the farthest frontier”
“don't go beyond the farthermost (or furthermost) tree”
“explored the furthest reaches of space”
“the utmost tip of the peninsula”
comparative
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for utmost come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.