demurrer n.

active word-forming element in English and in many verbs inherited from French and Latin, from Latin de "down, down from, from, off; concerning" (see de), also used as a prefix in Latin, usually meaning "down, off, away, from among, down from," but also "down to the bottom, totally" hence "completely" (intensive or completive), which is its sense in many English words.

As a Latin prefix it also had the function of undoing or reversing a verb's action, and hence it came to be used as a pure privative — "not, do the opposite of, undo" — which is its primary function as a living prefix in English, as in defrost (1895), defuse (1943), de-escalate (1964), etc. In some cases, a reduced form of dis-.

1875, originally a legal term for "authorization to a debtor to postpone due payment," from neuter of Late Latin moratorius "tending to delay," from Latin morari "to delay," from mora "pause, delay," from PIE *morh- "to hinder, delay" (source also of Sanskrit amurchat "to congeal, become solid;" Old Irish maraid "lasts, remains"). The word didn't come out of italics until 1914. General sense of "a postponement, deliberate temporary suspension" is recorded by 1932. Related: Moratorial.

c. 1200, demuren, "to linger, tarry, delay," a sense now obsolete, from variant stem of Old French demorer "delay, retard," from Latin demorari "to linger, loiter, tarry," from de- (see de-) + morari "to delay," from mora "a pause, delay" (see moratorium).

Modern sense of "raise objections, take exception, have scruples" is by 1630s, from a legal sense attested from the 1620s: "admit provisionally the facts of the opponent's proceeding but deny he is entitled to legal relief," a verb from demurrer. Such a pleading effectively stops the action until the point is settled. Related: Demurred; demurring.