Answer: guesser

AnswerCrossword Clue
GUESSERHe's not sure
GUESSER"Jeopardy!" contestant, at times
GUESSERCharade player
GUESSEREstimator
GUESSERSurmiser.
GUESSEROne who hopes he's right.
GUESSEROne taking a shot
GUESSERCharades participant, e.g.
GUESSERParticipant in hangman or charades
guesserone that guesses (to form an opinion from little or no evidence)