A nested tuplet in Music Theory is when a tuplet (a rhythmic grouping of notes) is divided into smaller tuplets within it. This creates complex rhythmic patterns and can add a sense of tension and excitement to the music.
Septuplets.
Could possibly be: Undectuplets, undentuplets or hendectuplets.
There is no prefix for it. Usually this is tuplet like octuplet.
If we name them the same as multiple births following the pattern of triplets, quadruplets, quintuplets, etc. it would be nonuplets.See Related links below.
Simply click a note, press 3 on your keyboard, and there's your triplet. You can also do this by clicking "Score" in the Noteflight menu and clicking "Create Tuplet" Hope that helped.