Wild fear about getting left (5)
I believe the answer is:
feral
'wild' is the definition.
(similar in meaning)
'fear about getting left' is the wordplay.
'about' indicates anagramming the letters.
'getting' is a charade indicator (letters next to each other).
'left' becomes 'l' (common abbreviation).
'fear' anagrammed gives 'fera'.
'fera'+'l'='FERAL'
(Other definitions for feral that I've seen before include "Flare up, being fierce" , "Wild or brutal" , "Wild but originally domestic" , "Wild (though once tame)" , "'Savage, wild (5)'" .)