Definition of Least

Adverb: least leest

Used to form the superlative
"The garter snake is the least dangerous snake";
- to the lowest degree

Adjective: least leest

The superlative of 'little' that can be used with mass nouns and is usually preceded by 'the'; a quantifier meaning smallest in amount, extent or degree
"didn't care the least bit"; "he has the least talent of anyone"

Noun: least leest

Something that is of no importance
"it is the least I can do"; "that is the least of my concerns"