Answer: sudden

AnswerCrossword Clue
SUDDEN

Out of the blue

SUDDEN

Abrupt

SUDDEN

Without warning

SUDDEN
"This is so ..!"
SUDDEN
Unexpected
SUDDEN... death (game-ending point)
SUDDENLike a sneak attack
SUDDENQuip, part 3
SUDDENComing out of the blue
SUDDENOut-of-the-blue
SUDDENUnforeseen.
SUDDENHasty.
SUDDENPrecipitate.
SUDDENAbrupt.
SUDDEN"This is so ...!"
SUDDENUnanticipated
SUDDENRash
SUDDENHappening without warning
SUDDENUnforeseen