Etymology

From Middle Persian bym ‎(bīm, “fear, fright, dread”), from Proto-Indo-Iranian *bajH-, from Proto-Indo-European *bʰeyh₂- ‎(“to fear”). From the same root also باک ‎(bâk, “fear; hesitation”). Cognate with Avestan [script needed] ‎(b(a)ii-, “to fear”), Sanskrit बिभेति ‎(√bhay-, “to fear”) (compare identical formation भीम ‎(bhīmá, “fearful”)), Old Church Slavonic боꙗти ‎(bojati, “to fear”) (Russian бояться ‎(bojáts'a)) and Old English bifian ‎(“to shiver”).