Dumpy one's in trouble for creating new identity (9)
I believe the answer is:
pseudonym
'creating new identity' is the definition.
I can't tell whether this defines the answer.
'dumpy one's in trouble' is the wordplay.
'in trouble' indicates anagramming the letters.
'dumpy'+'ones'='dumpyones'
'dumpyones' is an anagram of 'PSEUDONYM'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for pseudonym that I've seen before include "Goliath, for one" , "Pen name - use my pond (anag)" , "Pen-name" , "Name adopted by someone for a particular role" , "in the style of George Eliot?" .)