I. prefix
Etymology: Middle English, from Old French, from Latin, from Greek, from pro — more at for
1.
a. : earlier than : prior to : before
pro baptismal
b. : rudimentary : prot-
pro anthropus
Pro mammalia
pro embryo
2.
a. : situated before : located in front of : anterior to
pro cerebrum
b. : front : anterior
pro thorax
3. : projecting
pro gnathous
II. prefix
Etymology: Latin (also used especially with verbs to mean “before”, “forward”, “forth”, “down”, “on behalf of”), from pro before, in front of, in behalf of, for, on account of — more at for
1. : taking the place of : substituting for
pro cathedral
pro -regent
pro -treasurer
2. : siding with : advocating : favoring : supporting : championing
pro -British
pro -liberalism