Be lying when about to ask a question (6)
I believe the answer is:
repose
'be lying' is the definition.
(thesaurus)
'about to ask a question' is the wordplay.
I cannot really understand how this works, but
'about' could be 're' ('re' means regarding or about) and 're' is found within the answer.
'ask' could be 'pose' (synonyms) and 'pose' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'when' acts as a link.
Can you help me to learn more?
(Other definitions for repose that I've seen before include "calm" , "State of tranquillity" , "Relaxation" , "Rest - tranquillity" , "Quiet restfulness" .)