The trouble about a Spaniard is he's fond of pleasure (8)
I believe the answer is:
hedonist
'he's fond of pleasure' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'the trouble about a spaniard is' is the wordplay.
'trouble' indicates an anagram.
'about' is an insertion indicator.
'a spaniard' becomes 'don' (term for a Spanish gentleman).
'the' is an anagram of 'het'.
'don'+'is'='donis'
'het' going around 'donis' is 'HEDONIST'.
Can you help me to learn more?
(Other definitions for hedonist that I've seen before include "playboy" , "sybarite" , "He believes pleasure is the chief good in life" , "Epicurean" , "he puts pleasure before work" .)