New unusually red anorak (4)
I believe the answer is:
nerd
'anorak' is the definition.
(I've seen this before)
'new unusually red' is the wordplay.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'unusually' indicates an anagram.
'red' with letters rearranged gives 'erd'.
'n'+'erd'='NERD'
(Other definitions for nerd that I've seen before include "Boring, trivia-obsessed type" , "Irritating person (slang)" , "one that's overly cerebral" , "Student who is ridiculed for studying excessively" , "Boring person" .)