Emily Dickinson Lexicon

SEM'I-BREVE, n. [semi and breve; formerly written Semi-bref.]

In music, a note of half the duration or time of the breve, a note not now in use. The semibreve is the longest note now used, and the measure note by which all others are regulated. It contains the time of two minims, four crotchets, eight quavers, sixteen semiquavers and thirty-two demisemiquavers.