Fish, tons first, in web (6)
I believe the answer is:
tangle
'web' is the definition.
(thesaurus)
'fish tons first' is the wordplay.
I cannot really see how this works, but
'fish' could be 'angle' (angle can mean to fish) and 'angle' is found in the answer.
'tons' could be 't' and 't' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'in' is the link.
Can you help me to learn more?
(Other definitions for tangle that I've seen before include "Get involved" , "Jumbled mass" , "Confused mess" , "Twist confusedly" , "At glen (anag.)" .)