noun
good medicine; effective remedy
Refers to a medicine or treatment that is effective or beneficial. Can be used literally for pharmaceuticals or figuratively for a good solution.
この漢方薬は古くから良剤として知られている。
This herbal medicine has long been known as an effective remedy.
運動はストレスに良剤だ。
Exercise is a good medicine for stress.
Compound of 良 (good) and 剤 (medicine, dose). The exact historical derivation is uncertain, but the term follows a common Sino-Japanese pattern for describing types of medicines.