1. noun /ˈpæsərən,ˈpæsəriːn,ˈpæsəraɪn/
a) A large order (Passeriformes) of birds, comprising more than half of all bird species.
b) A bird member of the Passeriformes order.
2. adjective /ˈpæsərən,ˈpæsəriːn,ˈpæsəraɪn/
Of, or relating to a passerine or perching bird.
Wikipedia foundation.