least -
something that is of no importance; "it is the least I can do"; "that is the least of my concerns"
Adjective
least -
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"
superlative the superlative form of an adjective or adverb; "`fastest' is the superlative of the adjective `fast'"; "`least famous' is the superlative degree of the adjective `famous'"; "`most surely' is the superlative of the adverb `surely'"
Adverb
least -
used to form the superlative; "The garter snake is the least dangerous snake"