having shared your time or money on a situation, may be used to express one's frusration in a negitive manner or as positive to reflect satisfaction.

Or simply means you have no money left!
"i cant believe he's done this to me, i'm spent on him"

or after a hearty meal;
"that was delicious, i'm spent"

"im spent man, but check these dope threads!"
by fabzz29 February 23, 2012
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