What is "at erst"

Erst \Erst\ ([~e]rst), adv. [Orig. superlative of ere; AS.

1. First.
   --Chaucer.

2. Previously; before; formerly; heretofore.
   --Chaucer.

   Tityrus, with whose style he had erst disclaimed all ambition to match his pastoral pipe.
   --A. W. Ward.

   At erst, at first; at the beginning.

   Now at erst, at this present time.
   --Chaucer.