Rebellious Toby dyed his long jacket! (5,3)
I believe the answer is:
teddy boy
'his long jacket' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'rebellious toby dyed' is the wordplay.
'rebellious' indicates an anagram.
'toby'+'dyed'='tobydyed'
'tobydyed' is an anagram of 'TEDDY BOY'.
Can you help me to learn more?
(Other definitions for teddy boy that I've seen before include "Quiff owner of the 1950s" , "Follower of 1950s youth cult" , "Rebellious British youth of the 1950s" , "1950s' unruly youth" , "Yob of the 50s" .)