Bloomer made by many a leading aircraftman (5)
I believe the answer is:
lilac
'bloomer' is the definition.
Both the answer and definition are singular nouns.
Perhaps you can see a link between them that I don't see?
'made by many a leading aircraftman' is the wordplay.
'made by' says to put letters next to each other (letters written or made by another set of letters).
'many' becomes 'l'.
'a leading' becomes 'il' (I can't justify this - if you can you should believe this answer much more).
'aircraftman' becomes 'ac' (military abbreviation).
'l' put next to 'il' is 'lil'.
'lil'+'ac'='LILAC'
Can you help me to learn more?
(Other definitions for lilac that I've seen before include "Light-purple" , "Flower celebrated by Schubert" , "Light purple - flowering tree" , "Shrub (but not always this colour)" , "Shade" .)