IPA: /ˌdɛmɪˈsɛmɪˌkweɪvər/
KK: /dɛmɪˈsɛmɪˌkwɑːvər/
A musical note that lasts for a very short time, specifically one-thirtieth of a whole note, often represented by a specific symbol in sheet music.
In the piece, the composer used a demisemiquaver to create a rapid, lively rhythm.
Demisemiquaver → It is formed from "demi-" (from French, meaning half) and "semi-" (from Latin "semi-", meaning half) and "quaver" (from Old English "cwæfre", meaning to shake or tremble). The word refers to a musical note that is half the length of a sixteenth note, thus combining the meanings of half and quaver to describe a very short note.
Think of 'half' ('demi-' and 'semi-') and a note that 'shakes' or 'trembles' ('quaver') — this helps you remember that a demisemiquaver is a very short musical note.