Crossword Clue:

a card for use in the mail

Answer	Crossword Clue
LANCE	What a mail carrier might use in self-defense?
SLOT	Opening in a door for mail
BOXTOPTURTLE	Mail-in for a toy ninja?

CRIBBAGEBOARD	Place for pegs in a card game
YAKUZA	Japanese for "8, 9, 3," a losing hand in an old card game
LEANAGAINST	Use for support, in a way
STERILIZE	Make safe for use, in a way
COLORCODED	Labeled for easy use, in a way
POPOVER	For dropping in without calling beforehand, use a...
STASH	Store in a secret place for future use: Slang.