ire (n.)
c.1300, from Old French ire "anger, wrath, violence" (11c.), from Latin ira "anger, wrath, rage, passion," from PIE root *eis-, forming various words denoting "passion" cognates: Greek hieros "filled with the divine, holy," oistros "gadfly," originally "thing causing madness;" Sanskrit esati "drives on," yasati "boils;" Avestan aesma "anger").

Old English irre in a similar sense is from an adjective irre "wandering, straying, angry," cognate with Old Saxon irri "angry," Old High German irri "wandering, deranged," also "angry;" Gothic airzeis "astray," and Latin errare "wander, go astray, angry" (see err (v.)).