logic [OE] Logic came via Old French from late Latin, and from Greek logikē (tekhnē) ‘(art) of reason’; the base is Greek logos ‘word, reason’, found also in prologue [ME] ‘words said before’. Logo, a 1930s shortening of logogram, ‘a sign representing a word or phrase, shorthand’, or of the printing term logotype, ‘a single piece of type that prints a word, phrase, or symbol’ (both E19th) also goes back to logos.