The Collaborative International Dictionary of English v.0.48:

Protopope \Pro"to*pope\, n. [Proto- + pope: cf. F. protopope,
   Russ. protopop'.] (Gr. Ch.)
   One of the clergy of first rank in the lower order of secular
   clergy; an archpriest; -- called also protopapas.
   [1913 Webster]