Crackpot phoned in to obtain queen's personal number (9)
I believe the answer is:
endorphin
'personal number' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'crackpot phoned in to obtain queen's' is the wordplay.
'crackpot' is an anagram indicator (I've seen this in other clues).
'to obtain' indicates putting letters inside.
'queen' becomes 'r' (abbreviation for regina, e.g. in ER ).
'phoned'+'in'='phonedin'
'phonedin' with letters rearranged gives 'endophin'.
'endophin' enclosing 'r' is 'ENDORPHIN'.
Can you help me to learn more?
(Other definitions for endorphin that I've seen before include "Neurochemical with analgesic properties - dinner hop (anag)" , "Hormone in the brain with an analgesic effect" , "Opiate-like substance produced in the brain" , "painkiller" .)