Fiddlestick

The fiddlestick can produce different sounds depending on how it is used.

"He thought the missing pen was just a fiddlestick, until he realized it was his lucky pen."

"She considered the issue to be a fiddlestick and didn't give it much thought."

"Uh, let me think, fiddlestick, what was the name of that movie again?"

"I'm not quite sure how to answer that question, um, fiddlestick, I'll come back to it later."