adjective
superlative form of good: most good.
Most; largest.
Most superior; most favorable.
adverb
superlative form of well: most well
To the most advantage; with the most success, cause, profit, benefit, or propriety.
noun
(uncountable, often used after possessive determiners) The supreme effort one can make, or has made.
(uncountable, often used after possessive determiners) One's best behavior.
(countable, often used after definite article) The person (or persons; or thing or things) that is (are) most excellent.
verb
(transitive) To surpass in skill or achievement.
(transitive) To beat in a contest.
verb
(modal, colloquial) Had best.