didapper

noun2

1. •
   A small diving water bird frequenting rivers and fresh waters, specifically a little grebe or dabchick.

   • The misery of man may fitly be compar'd to a Di­dapper, who when she is under water, past our sight, and indeed can seem no more to us, rises again; […] — 1679
2. •
   (disapproving, no longer used) A scoundrel, a worthless person