maxime

Maxime is the superlative adverb of magnus, and the full ladder is magnopere, magis, maxime: greatly, more, most. Note that the adverbs are not built off the adjective in the ordinary way, which is why they have to be learned as a set rather than derived.

Beyond the plain superlative it does three other jobs. With an adjective it is an intensifier and simply means "very": vir maxime doctus. With quam in front it means "as much as possible", quam maxime, the same pattern as quam celerrime, "as fast as possible". And with cum in front, cum maxime, it means "at this very moment, precisely now", which looks nothing like the sum of its parts and is worth learning whole.

Standing alone in an answer, maxime is an emphatic yes, "most certainly", and immo vero maxime is stronger still. Its opposite number is minime, which is the ordinary Latin for "no". English took maximum, maximal and maximise from the adjective behind it.