Wasn't fast in the water either and was not among the winners (4-3)
I believe the answer is:
also-ran
'wasn't fast' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'water either and was not among the winners' is the wordplay.
I cannot really understand how this works, but
'either' could be 'or' (I've seen this in another clue) and 'or' is found within the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found in the answer.
This explanation may well be incorrect...
'in the' is the link.
Can you help me to learn more?
(Other definitions for also-ran that I've seen before include "Poor performer in race" , "Not among the first three in race" , "Not placed in the first three of horse race" , "Of racing horse, not placed in first three" , "Losing runner" .)