lubricous (adj.)

1530s, "lascivious," from Latin lubricus "slippery, slimy, smooth," figuratively "seductive," from suffixed form of PIE root *sleubh- "to slip, slide" (see sleeve). Literal meaning "slippery, oily" is from 1650s in English; figurative sense of "shifty, elusive" is from 1640s. Also lubricious (1580s).