pig noun, US 1: a: Applied contemptuously to a person; someone obstinate, annoying, greedy, etc. (1546 —) . P.G.Winslow I had some beautiful birds in London, but I had to stay on the good side of that pig, or she might have noticed more than was good for her (1977). b: Similarly, applied to a thing; something difficult or frustrating, etc. (1923 —) . F.Mullally Watch out for the potholes. It's a pig of a road (1978).
2: A police officer. (1811 —) . D.Lodge Any pig roughs you up, make sure you get his number (1975). 3: Any of various types of vehicle: a locomotive, truck, aeroplane, etc. (1898 —) . Times The Pig, the armoured vehicle most used in Belfast (1978). 4:pigs in blankets Formerly, oysters wrapped in bacon; now, a sausage-roll or frankfurter sandwich, etc. (1902 —) . 5:pigs (to you) Austral A derisive retort. (1906 —) . N.Culotta 'She's worn out.' 'Pigs she is. There's a lot of life in 'er yet' (1957). 6:in pig of a woman, pregnant. (1945 —) .
[In sense 6, from the standard use, of a sow.]
pig verb, orig and mainly US
to pig out To over-indulge or 'make a pig of oneself' by over-eating (on). Cf. pig-outnoun. (1978 —) . J.Fonda Troy and Vanessa...pig out for days on leftover Halloween candy (1981).