Greasy sauce in sight (6)

I believe the answer is:

slippy

'greasy' is the definition.
(thesaurus)

'sauce in sight' is the wordplay.
'sauce' becomes 'lip' (I've seen this in other clues).
'in' indicates putting letters inside.
'sight' becomes 'spy' (spying is a kind of sighting).
'lip' going inside 'spy' is 'SLIPPY'.

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app