A birdbath is a shallow dish of water in a garden for birds. Fill the birdbath, a stone birdbath, ice on the birdbath.
Birds need it as much for washing as for drinking, since clean feathers insulate and fly better. It must be shallow, no more than a few centimetres, and rough enough to grip, and in winter it matters more than food.
1nounbirdbathA shallow dish of water in a garden for birds.
“A robin splashed happily in the birdbath on the lawn.”
birdbath is a dish.
Bird plus bath, a plain compound of the twentieth-century garden.
From bird + bath.
Etymology from Wiktionary, CC BY-SA