The Collaborative International Dictionary
semibref
Semibreve \Sem"i*breve`\, n. [Pref. semi- + breve: cf. F. semi-breve, It. semibreve.] [Formerly written semibref.] (Mus.) A note of half the time or duration of the breve; -- now usually called a whole note. It is the longest note in general use.