least
noun
something that is of no importance
“it is the least I can do”
“that is the least of my concerns”
adjective
the superlative of `little' that can be used with mass nouns and is usually preceded by `the'; a quantifier meaning smallest in amount or extent or degree
“didn't care the least bit”
“he has the least talent of anyone”
Oppositesmost
adverb
used to form the superlative
“The garter snake is the least dangerous snake”
Synonymsto the lowest degreeOppositesmost
Source: WordNet 3.1, Princeton University