Sort of oil in sort of lamp (4)
I believe the answer is:
palm
'sort of oil' is the definition.
(as in palm oil)
'sort of lamp' is the wordplay.
'sort of' indicates an anagram.
'lamp' is an anagram of 'PALM'.
'in' is the link.
(Other definitions for palm that I've seen before include "Conceal in the hand" , "Obscure" , "Conceal magician" , "prize" , "Tree symbolising victory" .)