Will such oil spoil a lamp? (4)
I believe the answer is:
palm
'will such oil' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Maybe you can see a link between them that I don't see?
'spoil a lamp?' is the wordplay.
'spoil' is an anagram indicator.
'lamp' is an anagram of 'PALM'.
Can you help me to learn more?
(Other definitions for palm that I've seen before include "Sign of victory" , "Conceal magician" , "Leaf in part of the hand?" , "Secretly snatch" , "Use hand" .)