☞ icosi-
icosa-
combining form 
also icosi- or icos-
Etymology: Greek eikosa-, eikosi-, eikos-, from eikosi — more at vicenary 
 : twenty 
< icosahedron >
also icosi- or icos-
< icosahedron >
icosa-
Prefix
- twenty
Etymology
From Ancient Greek εἴκοσι (eíkosi, “twenty”).