Have A Chip On Your Shoulder Edit Meaning

1.

to be touchy, to be easily provoked (During the 19th century, a person in the united states would challenge others to a fight by placing a wooden chip on his/her shoulder and daring them to knock it off, and if the other person did so, the fight was on.)

Man, You sure do have a chip on your shoulder today.

See bad ass, idiom, touchy