Wrestler loses nothing in total (3)
I believe the answer is:
sum
'total' is the definition.
(I know that total can be written as sum)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for sum that I've seen before include "Whole" , "Total, add" , "Arithmetical problem" , "Mathematical problem" , "Add together" .)