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.
[1913 Webster]