sixty-fourth note

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A note having one sixty-fourth the time value of a whole note.

from The Century Dictionary.

• noun In musical notation, a note equivalent in time-value to one half of a thirty-seeond-note); a hemidemi-semiquaver: , or, in groups

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun music a note with 1/64 the value of a whole note

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a musical note having the time value of a sixty-fourth of a whole note