n.
1.a shelter with perches for fowl or other birds
2.a perch on which domestic fowl rest or sleep roost v.
1.sit, as on a branch
2.settle down or stay, as if on a roost
Idiom of the Day
sit in for (someone)
to take someone else's place in some activity
I asked my friend to sit in for me at my volunteer job at the community center.