Tailless aircraft still on the drawing board? (4)
I believe the answer is:
plan
'still on the drawing board?' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'tailless aircraft' is the wordplay.
'tailless' means to remove the last letter (the tail of the word is removed).
'aircraft' becomes 'plane' (plane is a kind of aircraft).
'plane' with its last letter taken away is 'PLAN'.
Can you help me to learn more?
(Other definitions for plan that I've seen before include "Formulate" , "Large-scale map" , "Layout drawing" , "Arrangement" , "Road map" .)