dizzyyoudaoicibaDictYouDict[dizzy 词源字典]
dizzy: [OE] Dizzy originally signified ‘foolish, stupid’, a meaning which from the 13th century retreated into dialectal use and has only comparatively recently returned to the mainstream language in the milder form ‘scatterbrained’. The now central sense ‘giddy’ is recorded from the 14th century. The word comes from a West Germanic base *dus-, which also produced Dutch duizelen ‘be giddy’. Its formal and semantic similarity to doze and tizzy are obvious, but no actual etymological link between the three seems ever to have been established.
[dizzy etymology, dizzy origin, 英语词源]
dizzy (adj.)youdaoicibaDictYouDict
Old English dysig "foolish, stupid," from Proto-Germanic *dusijaz (cognates: Low German düsig "dizzy," Dutch duizelen "to be dizzy," Old High German dusig "foolish," German Tor "fool," Old English dwæs, Dutch dwaas "foolish"), perhaps from PIE *dheu- (1) "dust, vapor, smoke; to rise in a cloud" (and related notions of "defective perception or wits").

Meaning "having a whirling sensation" is from mid-14c.; that of "giddy" is from c. 1500 and seems to merge the two earlier meanings. Used of the "foolish virgins" in early translations of Matthew xxv; used especially of blondes since 1870s. Related: Dizzily.
dizzy (v.)youdaoicibaDictYouDict
Old English dysigan, from source of dizzy (adj.). Related: Dizzied; dizzying.