mordant adj.

Proto-Indo-European root meaning "to rub away, harm." Possibly identical with the root *mer- that means "to die" and forms words referring to death and to beings subject to death.

It forms all or part of: amaranth; ambrosia; amortize; Amritsar; immortal; manticore; marasmus; mare (n.3) "night-goblin, incubus;" morbid; mordacious; mordant; moribund; morsel; mort (n.2) "note sounded on a horn at the death of the quarry;" mortal; mortality; mortar; mortgage; mortify; mortmain; mortuary; murder; murrain; nightmare; post-mortem; remorse.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit mrnati "crushes, bruises," mriyate "to kill," martave "to die," mrta- "died, dead," mrtih "death," martah "mortal man," amrta- "immortal;" Avestan miriia- "to die," miryeite "dies," Old Persian martiya- "man;" Hittite mer- "to disappear, vanish," marnu- "to make disappear;" Armenian meranim "to die;" Greek marainein "to consume, exhaust, put out, quench," marasmus "consumption," emorten "died," brotos "mortal" (hence ambrotos "immortal"); Latin mors (genitive mortis) "death," mori "to die;" Armenian merani- "to die;" Gothic maurþr, Old English morþ "murder;" Old Irish marb, Welsh marw "dead;" Lithuanian mirti "to die," mirtis "death;" Old Church Slavonic mreti "to die," mrutvu "dead;" Russian mertvyj, Serbo-Croatian mrtav "dead."

"first meal of the day," mid-15c., from the verbal phrase; see break (v.) + fast (n.). For vowel shift, see below. An Old English word for it was undernmete (see undern), also morgenmete "morning meal."

Spanish almuerzo "lunch," but formerly and still locally "breakfast," is from Latin admorsus, past participle of admordere "to bite into," from ad "to" + mordēre "to bite" (see mordant). German Frühstück is from Middle High German vruostücke, literally "early bit."

In common with almuerzo, words for "breakfast" tend over time to shift in meaning toward "lunch;" compare French déjeuner "breakfast," later "lunch" (cognate of Spanish desayuno "breakfast"), from Vulgar Latin *disieiunare "to breakfast," from Latin dis- "apart, in a different direction from" + ieiunare, jejunare "fast" (see jejune; also compare dine). Greek ariston in Homer and Herodotus was a meal at the break of day but in classical times taken in the afternoon.

The long/short vowel contrast in break/breakfast represents a common pattern where words from Old English have a long vowel in their modern form but a short vowel as the first element of a compound: Christ/Christmas, holy/holiday, moon/Monday, sheep/shepherd, wild/wilderness, etc.

late 15c., smorchen, "to discolor, to make dirty" (also compare bismorched, mid-15c.), a word of uncertain origin, perhaps (OED) from Old French esmorcher "to torture," which is perhaps also "befoul, stain," from es- "out" (see ex-) + morcher "to bite," from Latin morsus, past participle of mordēre "to bite" (see mordant). The sense perhaps was influenced by smear. The figurative meaning "dishonor, disgrace, discredit" is attested from 1820.