One in education originally named after Rita in play (7)
I believe the answer is:
trainee
'one in education' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'originally named after rita in play' is the wordplay.
'originally named' becomes 'nee' (I've seen this before).
'after' means one lot of letters go next to another.
'in play' indicates an anagram (letters play around).
'rita' anagrammed gives 'trai'.
'nee' put after 'trai' is 'TRAINEE'.
Can you help me to learn more?
(Other definitions for trainee that I've seen before include "One learning a job" , "New recruit" , "One being taught a job" , "As pupil" , "21 [TYRO]" .)