c.1200, "comprehensive, inclusive, full," from Latin generalis "relating to all, of a whole class" (contrasted with specialis), from genus (genitive generis) "stock, kind" (see genus). General store attested by 1810, American English; a general hospital (1737) is one not restricted to one class of persons or type of disease.
late 14c., "whole class of things or persons," from general (adj.). Meaning "commander of an army" is 1570s, shortening of captain general, from Middle French capitaine général. The English adjective was affixed to civic officer designations by late 14c. to indicate superior rank and extended jurisdiction.