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deflection (n.)[deflection 词源字典]: also (and with more etymological propriety) deflexion, c. 1600, from Latin deflexionem, noun of action from past participle stem of deflectere (see deflect). Both forms were present 17c., but the spelling with -c- has come to predominate.[deflection etymology, deflection origin, 英语词源]
genuflection (n.): "act of bending the knee," especially in worship, early 15c., from Middle French génuflexion (14c.) and directly from Medieval Latin genuflectionem (nominative genuflexio) "bending of the knee," noun of action from past participle stem of Late Latin genuflectere "genuflect," properly genu flectere "to bend the knee," from Latin genu "knee" (see knee (n.)) + flectere "to bend" (see flexible).
inflection (n.): early 15c., from Middle French inflexion and directly from Latin inflexionem (nominative inflexio) "a bending, inflection, modification," noun of action from past participle stem of inflectere (see inflect). For spelling, see connection. Grammatical sense is from 1660s.
reflection (n.): late 14c., reflexion, in reference to surfaces throwing back light or heat, from Late Latin reflexionem (nominative reflexio) "a reflection," literally "a bending back," noun of action from past participle stem of Latin reflectere "to bend back, bend backwards, turn away," from re- "back" (see re-) + flectere "to bend" (see flexible). Of the mind, from 1670s. Meaning "remark made after turning back one's thought on some subject" is from 1640s. Spelling with -ct- recorded from late 14c., established 18c., by influence of the verb.