"If all __ fails..." (4)

I believe the answer is:
else
(Other definitions for else that I've seen before include "Alternatively" , "Adverb meaning if not, otherwise" , "In addition, besides" , "Eels (anag)" , "Besides, otherwise" .)
I believe the answer is:
else
(Other definitions for else that I've seen before include "Alternatively" , "Adverb meaning if not, otherwise" , "In addition, besides" , "Eels (anag)" , "Besides, otherwise" .)