roost(noun, verb) noun1. a shelter with perches for fowl or other birdsDefinition categories: man–made, shelter2. a perch on which domestic fowl rest or sleepDefinition categories: man–made, perch verb1. sit, as on a branchSimilar word(s): perch, restDefinition categories: contact, sit2. settle down or stay, as if on a roostDefinition categories: change, root, settle