c.1200, "to irritate, annoy, provoke," from Old Norse angra "to grieve, vex, distress; to be vexed at, take offense with," from Proto-Germanic *angus (cognates: Old English enge "narrow, painful," Middle Dutch enghe, Gothic aggwus "narrow"), from PIE root *angh- "tight, painfully constricted, painful" (cognates: Sanskrit amhu- "narrow," amhah "anguish;" Armenian anjuk "narrow;" Lithuanian ankstas "narrow;" Greek ankhein "to squeeze," ankhone "a strangling;" Latin angere "to throttle, torment;" Old Irish cum-ang "straitness, want"). In Middle English, also of physical pain. Meaning "excite to wrath, make angry" is from late 14c. Related: Angered; angering.

mid-13c., "distress, suffering; anguish, agony," also "hostile attitude, ill will, surliness," from Old Norse angr "distress, grief. sorrow, affliction," from the same root as anger, v.. Sense of "rage, wrath" is early 14c. Old Norse also had angr-gapi "rash, foolish person;" angr-lauss "free from care;" angr-lyndi "sadness, low spirits."