"to lower in dignity, lower the standing of, debase," c. 1600, perhaps from de- "down" + mean (adj.) and modeled on debase. It is indistinguishable in some uses from obsolete demean (Middle English, from Old French demener; see demeanor) which likely influenced it and might be its ultimate source. It was much-criticized in late 19c. by purists (Fitzedward Hall, etc.), and Century Dictionary (1897) reports "the word is avoided by scrupulous writers." Related: Demeaned; demeaning.