noun
Refers to the dry, rough crust that forms over a healing wound.
転んでひざにかさぶたができた。
I fell and got a scab on my knee.
かさぶたをはがすと血が出るよ。
If you pick the scab, it will bleed.
Rarely used kanji form.
The origin is uncertain. It may be a compound of かさ (a sore or skin eruption) and ふた (lid, cover), but this is not confirmed.