Do they fly in slow motion? (4)
I believe the answer is:
owls
'do they fly' is the definition.
Although both the answer and 'do' are nouns, they are not in the same form of the noun.
'slow motion?' is the wordplay.
'motion?' indicates an anagram (I've seen 'motion' mean this).
'slow' anagrammed gives 'OWLS'.
'in' is the link.
Can you help me to learn more?
(Other definitions for owls that I've seen before include "Avian symbols of wisdom" , "Nocturnal bird" , "Nocturnal birds" , "Members of Parliament" , "Nocturnal hooters?" .)