Warrant gets severed unexpectedly (7)
I believe the answer is:
deserve
'warrant' is the definition.
(I've seen this before)
'severed unexpectedly' is the wordplay.
'unexpectedly' indicates anagramming the letters.
'severed' anagrammed gives 'DESERVE'.
'gets' is the link.
(Other definitions for deserve that I've seen before include "Justify" , "Be entitled to" , "Merit (something)" , "Show one is worthy" , "Warrant" .)