What is the meaning of Yabby?

Any of various freshwater crayfish, typically of the genus Cherax, valued as food, especially Cherax destructor of southeastern Australia.

A species of marine ghost shrimp, Trypaea australiensis, widely harvested by recreational anglers as bait; a nipper.

To search, forage, or fish for yabbies.

To show disrespect by denouncing or insulting; to diss.

Source: wiktionary.org