Meaning

noun a transmission line for high-frequency signals

verb influence or urge by gentle urging, caressing, or flattering

originOriginally (1586) in the slang phrase to make a coax of, from earlier noun coax, cox, cokes "fool, simpleton", itself of obscure origin, perhaps related to cock (“male bird, pert boy”). The modern spelling is from 1706.

Etymology from Wiktionary, CC BY-SA 3.0