A group reformed there (5)
I believe the answer is:
three
'a group' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'reformed there' is the wordplay.
'reformed' is an anagram indicator.
'there' anagrammed gives 'THREE'.
Can you help me to learn more?
(Other definitions for three that I've seen before include "Start to count back, briefly" , "... number of his "Steps to Heaven"" , "Subject of 1 9" , "trilogy" , "Square root of nine" .)