water wing

Meanings

1. One of two walls built on either side of the junction of a bridge with the bank of a river, to protect the abutment of the bridge and the bank from the action of the current.
2. Synonym of armband (“one of a pair of inflatable plastic bands, normally worn on the upper arms, to help the wearer (often a child) float in water and learn to swim”).

Etymology

From water + wing. Compare German Schwimmflügel (“water wing”, literally “swim-wing”).