hemiola

noun

hemi·​o·​la ˌhe-mē-ˈō-lə 

: a musical rhythmic alteration in which six equal notes may be heard as two groups of three or three groups of two

Word History

Etymology

Late Latin hemiolia, from Greek hēmiolia ratio of one and a half to one, from hēmi- + holos whole — more at safe

First Known Use

circa 1934, in the meaning defined above