She's left in the stormy sea (4)
I believe the answer is:
elsa
'she's' is the definition.
'left in the stormy sea' is the wordplay.
'left' becomes 'l' (common abbreviation).
'in' means one lot of letters goes inside another.
'the stormy' indicates anagramming the letters (stormy suggests disruption).
'sea' with letters rearranged gives 'esa'.
'l' going inside 'esa' is 'ELSA'.
(Other definitions for elsa that I've seen before include "Girl" , "Big cat" , "Lioness (born free in Kenya)" , "___ Schiaparelli, Italian-born French fashion designer d. 1973" , "Famous lioness" .)