Answer: beatsme

AnswerCrossword Clue
BEATSME

"I haven't a clue!"

BEATSME

Dull student's response

BEATSME

"Who knows?"

BEATSME
"Not a clue!"
BEATSME
"I dunno"
BEATSME"No idea"
BEATSME"Darned if I know"
BEATSMEWords from the bewildered
BEATSMERemark of the puzzled
BEATSME"I don't have a clue!"
BEATSMEClueless one's comment
BEATSMEUnhelpful answer
BEATSME"That's tough!"
BEATSMEShrugger's remark
BEATSME"Dunno"
BEATSME"I have no idea!"
BEATSMEExpression of bafflement
BEATSME"Who knows?!"
BEATSMEComment made with a shrug
BEATSME"No clue"
BEATSME-
BEATSME"I haven't the foggiest"
BEATSME"No clue!"
BEATSME"How should I know?"
BEATSME"Heck if I know"