مَرْعَشٌ

A kind of pigeons that soar in their flight and circle in the air; as also ↓ مُرْعَشٌ: (S, K:) the latter form being sometimes used: (S:) or this signifies the white pigeon: or, according to Abu-l-'Alà, the vulture (نَسْر) that has become extremely aged, or old and weak. (Ham p. 823.)