RAF accepts doubtful UFO? (10)
I believe the answer is:
spacecraft
'ufo?' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'raf accepts doubtful' is the wordplay.
'doubtful' indicates anagramming the letters.
'raf'+'accepts'='rafaccepts'
'rafaccepts' is an anagram of 'SPACECRAFT'.
Can you help me to learn more?
(Other definitions for spacecraft that I've seen before include "could be a UFO" , "Astronauts' vehicle" , "Challenger, perhaps" , "vehicle going well beyond its normal range" , "UFO perhaps" .)