Answer: slicked

AnswerCrossword Clue
SLICKEDOiled (down)
SLICKEDAdded gel to, perhaps
slickedCover with a film of liquid; make wet or slippery
slickedMake (one's hair) flat, smooth, and glossy by applying water, oil, or cream to it
slickedSLICK, to tidy up, polish
slickedMake someone or something smart, tidy, or stylish