noun
mouthwash; gargle
Medical term for a liquid preparation used to rinse or gargle the mouth and throat.
歯科医は含嗽剤を処方した。
The dentist prescribed a mouthwash.
うがい薬 is the common everyday term for mouthwash or gargle, while 含嗽剤 is a formal medical term.
Compound of 含嗽 (gargling) and 剤 (medicine, preparation). The exact historical derivation is uncertain; the spelling is conventionally associated with medical use.