c. 1300 as an adverbial phrase, "completely, thoroughly, to the utmost degree," from out (adv.). Adjective usage is attested by 1813.
1844, "to act as an optimist, take the most hopeful view of a matter," a back-formation from optimist. Meaning "to make the most of, develop to the utmost" is attested by 1857. Related: Optimized; optimizing.
name of one of the 12 tribes of ancient Israel or its territory, named for its founder; literally "he who judges," related to Hebrew din "to judge." In the Old Testament, it occupied the northernmost part of Israel, hence its use proverbially for "utmost extremity," as in from Dan to Beersheba (the southernmost region), 1738. Related: Danite.
c. 1500, "complete, perfect, carried to the utmost extent or degree," from Latin consummatus "perfected, complete," past participle of consummare "sum up, complete," from assimilated form of com "together, with" (see con-) + summa "sum, total," from summus "highest" (see sum (n.)). Of persons, "accomplished, very qualified," from 1640s. Related: Consummately.