Informal term often used to describe something cute.
Esa niña es una verdadera monada, siempre sonríe y trae alegría a todos a su alrededor.
That girl is a real cutie; she always smiles and brings joy to everyone around her.
Esa niña es una verdadera monada; su risa ilumina la habitación.
That girl is a true cutie; her laughter brightens the room.