A lot of wrestling in total (3)
I believe the answer is:
sum
'total' is the definition.
('sum' can be a synonym of 'total')
'a lot of wrestling' is the wordplay.
'a lot of' means to remove the last letter (most of the word but not all of it).
'wrestling' becomes 'sumo' (I've seen this before).
'sumo' with its last letter taken off is 'SUM'.
'in' is the link.
(Other definitions for sum that I've seen before include "Arithmetic calculation" , "See 25" , "maths problem" , "Amount, aggregate" , "Quantity obtained by addition" .)