Type seen in this or that (4)
I believe the answer is:
sort
'type' is the definition.
(I know that type can be written as sort)
'in this or that' is the wordplay.
'in' says the answer is hidden in the clue.
'SORT' can be found hidden inside 'this or that'.
'seen' acts as a link.
(Other definitions for sort that I've seen before include "The kind to categorise" , "Group" , "Type - arrange in groups" , "Work out" , "Separate - kind" .)