Superlative form of greasy: most greasy.(adjective)
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Use "greasiest" in a sentence
"His whole brand is built around the proposition that he's a world expert on human rights, nationalism, and the perils and prospects of liberal interventionism, but whenever someone asks him his opinion on a specific case, Ignatieff slips and slides like the greasiest city hall politico."
"At the beauty salon one woman would order the thickest, greasiest cheeseburger and chips – and you could tell it was a guilty pleasure."
"Apr 5th, 2010 at 2: 11 pm kcijones001: this has to be the messiest, greasiest thing to eat."