aroost

From a- (“on”) +‎ roost.

aroost (comparative more aroost, superlative most aroost)

1. Of a bird, roosting.
   • 2008, Nicholas Drayson, A Guide to the Birds of East Africa, page 72:

     But anyone with that many large brown birds aroost in his cranium and that much gas in his bottom was clearly not a well person.

• Rosato