Crossword Genius

A fish setting agent (4)

Ross

I believe the answer is:

agar

I'm a little stuck... Click here to teach me more about this clue!

'agent' is the definition.
The definition and answer can be both substances as well as being singular nouns.
Maybe there's an association between them I don't understand?

'a fish' is the wordplay.
'fish' becomes 'gar' (gar is a kind of fish).
'a'+'gar'='AGAR'

'setting' acts as a link.

Can you help me to learn more?

(Other definitions for agar that I've seen before include "found in the sea" , "contribution to culture?" , "used in making soups?" , "Gelatinous substance from seaweed used as a thickener in foods." , "Food thickening agent obtained from seaweed" .)

I've seen this clue in the Sydney Morning Herald.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.