5.[countableC usually singular] technicalAPM the first note in a musicalscale of eight notes 〔音阶中的〕主音
Examples from the Corpus
tonic• It was a tonic we needed.• I'll have a gin and tonic.• He said he had drunk eight to 10 pints of lager and some vodka and tonic, the court was told.• It was good tonic for me to watch this.• There was a lot of hair tonic in evidence.• an herbaltonic• And remember, nothing - no skin tonic, astringent, freshener or plaincold water - can close your pores.• Humor was the tonic that brought Reeves out of his depression.