Pose adopted by boy in a state? (7)
I believe the answer is:
alaskan
'a state?' is the definition.
(I've seen this before)
'pose adopted by boy' is the wordplay.
'pose' becomes 'ask' (synonyms).
'adopted by' is an insertion indicator (I've seen this in other clues).
'boy' becomes 'alan' (I've seen this before).
'ask' put inside 'alan' is 'ALASKAN'.
'in' acts as a link.
(Other definitions for alaskan that I've seen before include "Person from state that's not so warm" , "From Anchorage, perhaps" , "Palin, perhaps" , "in an often frozen state?" , "one used to harsh conditions" .)