know-everything

noun2

1. •
   A highly knowledgeable person; expert.

   • Lots of people are like that in our business, trying to act like complete know-everythings. — 1981
2. •
   Synonym of know-it-all.

   • There is Mali, there is Guinea, you are about to say— but our loans to Mali and Guinea, my young know-everythings, are like fish to vultures; the stomach remains empty. — 1984