Answer:

YOULOSE

Answer	Crossword Clue
YOULOSE	"Checkmate!"
YOULOSE	"Checkmate"
YOULOSE	"Heads I win; tails ..."

YOULOSE	" . . . tails ..."
YOULOSE	"Heads I win, tails ..."
YOULOSE	Coin flipper's declaration
YOULOSE	Poor sport's taunt
YOULOSE	Calvin Coolidge's reputed reply to a woman who bet she could get more than two words out of him
YOULOSE	"Mate!"
YOULOSE	Bad sport's taunt
YOULOSE	Victor's gloating cry