demisemiquaver

“Thus they call a double whole note a breve, a whole note a semibreve, a half note a minim, a quarter note a crotchet, an eighth note a quaver, a sixteenth note a semi-quaver, a thirty-second note a demisemiquaver, and a sixty-fourth note a hemidemisemiquaver, or semidemisemiquaver.”

Chapter 4. American and English Today. 2. Differences in Usage

“Remember, you've got to begin on the demisemiquaver at the end of the bar -- only not too staccato, remember -- and allow for the pause.”

Somehow Good

“But you must not vigorously move immediately from semiquavers to demisemiquavers, as in this example, or from these to the next in degree -- that would be doubling the velocity of the shake all at once, which would be a skip, not a graduation; but you can imagine between a semiquaver and a demisemiquaver intermediate degrees of rapidity, quicker than the one, and slower than the other of these characters; you are therefore to increase in velocity by the same degrees in practising the shake, as in loudness when you make a swell.”

The Violin Its Famous Makers and Their Imitators