The common weasel, little weasel, or simply weasel (Mustela nivalis), the smallest member of the weasel genus Mustela, native to Eurasia, North America, and North Africa.

One who goes first. / One having authority to direct. / One who leads a political party or group of elected party members; sometimes used in titles.

(idiomatic) To engage in self-improvement; to begin a good habit or shed a bad habit.

(focus) At the least; at a minimum or lower limit. / In any event; anyway.

The most little; the smallest amount or quantity of something.

Used for forming superlatives of adjectives, especially those that do not form the superlative by adding -est. / In the smallest or lowest degree; in a degree below all others.

(philosophy) Something of the smallest possible extent; an indivisible unit.

(archaic, outside of fixed terms) superlative degree of little; smallest

(informal, nonstandard) At least. / 2019 December, Justin Blackburn, The Bisexual Christian Suburban Failure Enlightening Bipolar Blues, page 79:

(usually used in the plural) A dried fragment of a leaf of the tea plant used in making the drink tea. / (Cockney rhyming slang) A thief.