Sycophant

A servile self-seeking flatterer; one who praises those in power in order to gain their approval. Also: sycophantic (adj).

First attested in 1537. From Latin sȳcophanta (“informer, trickster”), from Ancient Greek συκοφάντης (sukophántēs), itself from σῦκον (sûkon, “fig”) + φαίνω (phaínō, “to show, demonstrate”). The gesture of "showing the fig" was a vulgar one, which was made by sticking the thumb between two fingers, a display which vaguely resembles a fig, which is itself symbolic of a σῦκον (sûkon), which also meant vulva. The story behind this etymology is that politicians in ancient Greece steered clear of displaying that vulgar gesture, but secretly urged their followers to taunt their opponents by using it

ass-kisser, brown-noser, suck-up, yes-man