Source : Webster's Revised Unabridged Dictionary (1913)

Semiquaver \Sem"i*qua`ver\, n. (Mus.)
   A note of half the duration of the quaver; -- now usually
   called a sixsteenth note.

Source : WordNet®

semiquaver
     n : a musical note having the time value of a sixteenth of a
         whole note [syn: {sixteenth note}]