yawny

adjective3

1. •
   Prone to yawning.

   • Waking up in the small room, you feel dull, stupid, gloomy, oppressed, yawny, lax, and all unstrung in body and mind... — 1848
2. •
   Boring, uninteresting, causing yawns.
3. •
   Sounding like a yawn.

   • I drew the deepest, yawniest breath I could fake and swiftly lifted my right arm. — 2011