Seriously premature to enter hideout? On the contrary (9)
I believe the answer is:
earnestly
'seriously' is the definition.
(I know that seriously can be written as earnestly)
'premature to enter hideout? on the contrary' is the wordplay.
I cannot quite see how this works, but
'hideout?' could be 'nest' (I've seen this in another clue) and 'nest' is present in the answer.
'premature' could be 'early' (similar in meaning) and 'early' is found in the remaining letters.
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 earnestly that I've seen before include "with gusto" , "Showing commitment" , "with heart and soul" , "Relent, say, in sincere and serious manner" , "Showing serious intent" .)