What does "angler" mean?

Angler: (Zoöl.) A fish (Lophius piscatorius), of Europe and America, having a large, broad, and depressed head, with the mouth very large. Peculiar appendages on the head are said to be used to entice fishes within reach. Called also fishing frog, frogfish, toadfish, goosefish, allmouth, monkfish, etc.