A medicine or treatment that relieves pain; a painkiller or analgesic.
頭が痛いので痛み止めを飲んだ。
My head hurt, so I took a painkiller.
手術後は痛み止めが切れると強い痛みが戻った。
After the operation, the pain came back strongly when the painkiller wore off.
旅行には常備薬として痛み止めを持って行くと安心だ。
It's reassuring to take a painkiller as a standard medicine when traveling.
医師は市販の痛み止めで十分だと言った。
The doctor said an over-the-counter painkiller would be sufficient.