Apprehensive rising star confused over lines (7)
I believe the answer is:
nervous
'apprehensive' is the definition.
(synonyms)
'rising star confused over lines' is the wordplay.
'rising' shows that the letters should be reversed in order (letters written upwards in a down clue).
'star' becomes 'sun' (the Sun is a star).
'confused' indicates anagramming the letters.
'lines' is an insertion indicator (inserted letters line the inside of others).
'sun' backwards is 'nus'.
'over' with letters rearranged gives 'ervo'.
'nus' enclosing 'ervo' is 'NERVOUS'.
(Other definitions for nervous that I've seen before include "Easily agitated, timid" , "in a stew" , "Feeling or showing anxiety" , "Edgy" , "Easily alarmed" .)