It would take long legs to make him a flier! (5)
I believe the answer is:
daddy
'a flier' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'it would take long legs to make him' is the wordplay.
I cannot really understand how this works, but
'would' could be 'd' (I've seen this in other clues) and 'd' is found within the answer.
'him' could be 'addy' and 'addy' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for daddy that I've seen before include "pop" , "Papa" , "Pa" , "Child's father" , "Informal father" .)