forming the superlative of adjectives and adverbs, esp. those of more than one syllable: the most important event of my life; sandy plains where fire tends to spread most quickly. 3 extremely; very: it was most kind of you; that is most probably correct. 4 INFORMAL almost: most everyone understood. # at (the) most not more than: the walk took four minutes at the most. # be the most INFORMAL be the best of all; be the ultimate. # for the most part in most cases; usually: the older members, for the most part, shun him. # make the most of use to the best advantage: