A form of extremely localized corrosion that leads to the creation of small holes in the metal.

(slang) A drive-in theatre or other unlit or dimly-lit secluded public or private location, with particular reference to it as a place of intimacy.

plural of pit viper

(Tyneside, derogatory) A term of abuse directed at inhabitants of mining villages of County Durham and Northumberland. / (Tyneside) Someone who speaks pitmatic.

plural of sump pit

(intransitive, car racing) To leave the pits and go out onto the race track / (intransitive, of a machine) To stop working / (intransitive) To show sweat on one's clothes, especially around the armpits.

(idiomatic) A possession or financial commitment, especially a building or vehicle, that creates substantial ongoing expenses, especially one whose costs are considered to be unsustainable.

(sometimes capitalized) Long-standing nickname of a complicated, seemingly man-made excavation on Oak Island in Nova Scotia, Canada, rumored to contain pirate treasure and which has been repeatedly and unsuccessfully probed at great expense.

(anatomy) A deep ciliated fossa on the dorsal midline of the buccal cavity in lancelets.

Any of various venomous snakes of the family Crotalinae, found in Asia and the Americas, with a deep pit or groove on either side of the head which enables them to detect prey by infrared sensing; a pit viper.