What kind of key is this?

[foundation hunter]

Found this key in the front yard of a 1740 colonial,the shaft is tapered its not broken off.

 

[Tony in SC]

Could be a clock key. Tony

 

[foundation hunter]

Could be a clock key. Tony

Mabe its for a musical instrument.

 

[dozer dan]

tuning key for a stringed instrument?

what doe's the inside of the hole look like?

round, square?

 

[sniffer]

that's a locking pin for an old style single hung window.
when the window was closed you would push that through a hole in the bottom window, upper right corner,
which would enter another hole in the upper window to keep it "locked"