Problem with wrestling, nothing less (3)
I believe the answer is:
sum
'problem' is the definition.
(arithmetic problem)
'wrestling nothing less' is the wordplay.
'wrestling' becomes 'sumo' (I've seen this before).
'nothing' becomes 'o' (looks like zero - 0).
'less' indicates named letters should be taken away.
'sumo' with 'o' taken away is 'SUM'.
'with' is the link.
(Other definitions for sum that I've seen before include "Aggregate, total" , "Amount of money; add" , "Add together" , "maths problem" , "See 25" .)