noun
old wound; scar
Refers to a physical injury from the past that may have left a scar or still causes trouble.
古傷が寒くなると痛む。
My old wound aches when it gets cold.
彼の腕には古傷の跡が残っている。
A scar from an old wound remains on his arm.
noun
painful memory; past misdeed; old skeleton in the closet
Metaphorical use for an unpleasant past experience, a regret, or a past wrongdoing that still affects someone emotionally or socially.
その話は彼にとって古傷をえぐるようなものだ。
That story is like reopening an old wound for him.
政治家の古傷が選挙で蒸し返された。
The politician's past misdeed was brought up again during the election.
Compound of 古 (old) and 傷 (wound). The metaphorical sense developed naturally from the idea of an old injury that still causes pain.