Can opener of a sort (3)
I believe the answer is:
tab
'can opener of a sort' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tab that I've seen before include "Tag" , "Flap; meal bill" , "Bar tally; small flap" , "Flap; illicit drug pill (slang)" , "Small flap - bill" .)