asphyxiate (v.)

1706, "stoppage of pulse, absence of pulse," from Modern Latin asphyxia "stopping of the pulse," from Greek asphyxia "stopping of the pulse," from a- "not" (see a- (3)) + sphyzein "to throb, to beat violently," which is of unknown origin.

Obsolete in its original sense; the transferred sense of "suffocation, extreme condition caused by lack of oxygen in the blood" is from 1778, but it is a "curious infelicity of etymology" [OED] because victims of suffocation have a pulse for some time after breathing has stopped. Formerly sometimes nativized as asphyxy. Related: Asphyctic; asphyxial.

verbal suffix for Latin verbs in -are, identical with -ate (1). Old English commonly made verbs from adjectives by adding a verbal ending to the word (such as gnornian "be sad, mourn," gnorn "sad, depressed"), but as the inflections wore off English words in late Old and early Middle English, there came to be no difference between the adjective and the verb in dry, empty, warm, etc. Thus accustomed to the identity of adjectival and verbal forms of a word, the English, when they began to expand their Latin-based vocabulary after c. 1500, simply made verbs from Latin past-participial adjectives without changing their form (such as aggravate, substantiate) and it became the custom that Latin verbs were Englished from their past participle stems.

"act of causing asphyxia," 1849, noun of action from asphyxiate (v.).