Definition of sesquialteral:
(adj) :
(music) Of or related to sesquialtera, 1½ notes.
(adj) :
(mathematics, archaic) Synonym of sesquialterate, 1½ times.
(adj) :
(botany, archaic) Having full florets accompanied by lesser ones.
(adj) :
(botany, archaic) Having half as many stamens as petals.
(adj) :
(entomology, archaic) Occupying a third of a wing or including a smaller band or spot in a larger one.