What does "clingfish" mean?

A small marine fish of the family Gobiesocidae which has a sucking disc on its underside that it uses to cling to rocks and seaweed.

Clingfish

Common synonyms include: adhesive disc, adhesive disc fish, cling goby, gobiesocid fish, suction disc, ventral disc.

noun

noun ·Rare ·Advanced level

Noun

1
A small marine fish of the family Gobiesocidae which has a sucking disc on its underside that it uses to cling to rocks and seaweed.
2
very small (to 3 inches) flattened marine fish with a sucking disc on the abdomen for clinging to rocks etc. wordnet

From cling + fish.