Became weary and impatient while being drilled (5)
I believe the answer is:
bored
'being drilled' is the definition.
(I've seen this in another clue)
'became weary and impatient while' is the wordplay.
I cannot quite see how this works, but
'weary' could be 'bore' (as a verb) and 'bore' is found in the answer.
A single letter 'd' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for bored that I've seen before include "Drilled; fed up" , "Weary; drilled" , "Short of things to do, maybe" , "Used drill on" , "Suffering from ennui" .)