Here's what rhymes with spheroidal.

Consider these alternatives

prolate / late oblate / late chlamydospores / course sigmoidal / colloidal sinusoidal / colloidal dwarf / course starburst / first cholecystokinin / meaning amacrine / line chelated / created secretin / region convolution / solution pyriform / form aglycone / known ghrelin / one globular / popular concretions / presence