I. ˈət-ˌmōst, especially Southern -məst adjective
Etymology: Middle English, alteration of utmest, from Old English ūtmest, superlative adjective, from ūt out, adverb — more at out
Date: before 12th century
1. : situated at the farthest or most distant point : extreme
the utmost point of the earth — John Hunt
2. : of the greatest or highest degree, quantity, number, or amount
a matter of utmost concern
II. noun
Date: before 12th century
1. : the most possible : the extreme limit : the highest attainable point or degree
the utmost in reliability
2. : the highest, greatest, or best of one's abilities, powers, and resources
will do our utmost to help