late 14c., from O.Fr. adulacion, from L. adulationem (nom. adulatio), from adulatus, pp. of aduliari "to flatter," from ad- "to" + ulos "tail," from PIE *ul- "the tail" (cf. Skt. valah "tail," Lith. valai "horsehair of the tail"). The original notion is "to wag the tail" like a fawning dog (cf. Gk. sainein "to wag the tail," also "to flatter;" see also wheedle).