electrocute v.

before vowels electr-, word-forming element meaning "electrical, electricity," Latinized form of Greek ēlektro-, combining form of ēlektron "amber" (see electric). As a stand-alone, formerly often short for electrotype, electroplate.

late 14c. "to carry into effect" (transitive, mostly in law with reference to warrants, sentences, etc.), also "carry out or accomplish a course of action" (intransitive), from Old French executer (14c.), from Medieval Latin executare, from Latin execut-/exsecut-, past participle stem of exequi/exsequi "to follow out, to follow to the grave," figuratively "to follow, follow after, accompany, follow up, prosecute, carry out, enforce; execute, accomplish; punish, avenge," from ex- "out" (see ex-) + sequi "follow" (from PIE root *sekw- (1) "to follow"). Meaning "to inflict capital punishment" is from late 15c., from earlier legal sense "perform judgment or sentence on" (early 15c.). Related: Executed; executing.

"execution by electricity," 1889, American English; noun of action from electrocute. Meaning "any death by electricity" is from 1897.

Electrocution, unless better performed than in the first instance, is a retrograde step rather than the contrary. The preliminary arrangements: the shaving of the head, the cutting of the clothing, the strapping in a chair, add much to the horror of the occasion. It is safe to say that electrocution is not the coming method of execution. [The Medical Era, vol. vii, no. 9, Sept. 1890]