The person or thing in the eleventh position. / One of eleven equal parts of a whole. / (music) The note eleven scale degrees from the root of a chord.

The ordinal form of the number eleven.

(idiomatic) A point in time which is nearly too late; the last minute.

(US, education) The period in school that comes after tenth grade and before twelfth grade.

The terrorist attacks that took place in the United States on September 11, 2001.

(nonce word) Twenty-one (21). / (colloquial) A relatively large number, not precisely specified. / (colloquial) A nonsense number.

Just before it is too late; in the nick of time; last-minute.

(Britain, informal) A short mid-morning break taken around eleven o'clock for a drink or light snack.

(informal) The number 110, 11 × 10. / (colloquial) An indefinite large number.

(archaic) Two hundred and twenty.