Spinet \Spin"et\, n. [OF. espinete, F. ['e]pinette (cf. It. spinetta), fr. L. spina a thorn; -- so called because its quills resemble thorns. See {Spine}.] (Mus.) A keyed instrument of music resembling a harpsichord, but smaller, with one string of brass or steel wire to each note, sounded by means of leather or quill plectrums or jacks. It was formerly much used. {Dumb spinet}. (Mus.) See {Manichordon}.