Row about good contender taking things seriously? (5)
I believe the answer is:
tiger
'contender taking things seriously?' is the definition.
I can't tell whether this defines the answer.
'row about good' is the wordplay.
'row' becomes 'tier' (tier is a kind of row).
'about' means one lot of letters goes inside another.
'good' becomes 'g' (abbreviation).
'tier' going around 'g' is 'TIGER'.
(Other definitions for tiger that I've seen before include "Striped feline" , "One noted for stripes" , "he got his stripes" , "Fierce, determined type" , "Beast - type of 1 across" .)