トニックトニックFreq.FrequencyTop 100,000Meanings1nountonicRefers to tonic water, hair tonic, or a musical tonic. Context determines the specific meaning.ジン・トニックをください。I'll have a gin and tonic, please.この曲きょくのトニックはハ長ちょう調ちょうです。The tonic of this piece is C major.