To perform menial or routine tasks

A male donkey. / (chiefly US) A foolish or stupid person. / (chiefly US) An inappropriately rude or obnoxious person. / (US, slang, uncountable) A kind of bootleg liquor.

(rare, intransitive) To behave very obnoxiously.

(poker slang) A jack and an ace as a starting hand in Texas hold 'em.

any of several large North American hares of the genus Lepus

(US) To make a sudden, rapid movement

A piece of clothing worn on the upper body outside a shirt or blouse, often waist length to thigh length. / A piece of a person's suit, beside trousers and, sometimes, waistcoat; coat (US)

To confine (someone) to a straitjacket. / (transitive) To enclose or encase in a jacket or other covering.

Alternative spelling of jack-knife

Alternative spelling of jack-knife