UTMOST

farthermost, farthest, furthermost, furthest, utmost, uttermost

(adjective) (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”

last, utmost

(adjective) 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”

extreme, utmost, uttermost

(adjective) of the greatest possible degree or extent or intensity; “extreme cold”; “extreme caution”; “extreme pleasure”; “utmost contempt”; “to the utmost degree”; “in the uttermost distress”

utmost, uttermost, maximum, level best

(noun) the greatest possible degree; “he tried his utmost”

Source: WordNet® 3.1

Etymology

Adjective

utmost (not comparable)

Situated at the most distant limit; farthest.

The most extreme; ultimate; greatest.

Noun

utmost (countable and uncountable, plural utmosts)

Maximum; greatest possible amount or quantity.

Source: Wiktionary

Ut"most`, a. Etym: [OE. utmeste, utemest, AS. , a superlative fr. out. Out, and cf. Aftermost, Outmost, Uttermost.]

1. Situated at the farthest point or extremity; farthest out; most distant; extreme; as, the utmost limits of the land; the utmost extent of human knowledge. Spenser. We coasted within two leagues of Antibes, which is the utmost town in France. Evelyn. Betwixt two thieves I spend my utmost breath. Herbert.

2. Being in the greatest or highest degree, quantity, number, or the like; greatest; as, the utmost assiduity; the utmost harmony; the utmost misery or happiness. He shall answer . . . to his utmost peril. Shak. Six or seven thousand is their utmost power. Shak.

Ut"most`, n.

Definition: The most that can be; the farthest limit; the greatest power, degree, or effort; as, he has done his utmost; try your utmost. We have tried the utmost of our friends. Shak.

Source: Webster’s Unabridged Dictionary 1913 Edition