Answer:

TROU

Answer	Crossword Clue
TROU	Pants, briefly
TROU	Lascaux cave
TROU	Short pants?

TROU	Pants, shortened
TROU	Shortened pants?
TROU	Drop ... (moon)
TROU	Moon droppings?
TROU	They're dropped by a fellow about to streak
TROU	Drop ... (pull a mooning prank)
TROU	Slacks, briefly
TROU	Slangy slacks

TROU	Briefs covering, in brief
TROU	Hole: Fr.
TROU	Hole, in France
TROU	Hole, in Paris
TROU	...-de-loup (military pit)
TROU	Gap, in Grenoble
TROU	Drop ... (start to strip)
TROU	Cut-off pants?

TROU	Drop ...
TROU	Pants, in brief
TROU	Drop ... (start to disrobe)
TROU	Pants, slangily
TROU	Pants, in slang
TROU	Drop ... (pants oneself)
TROU	...-de-loup (military trap)
TROU	What may descend before the moon?