n. & adj.
--n.
1. the position in a sequence corresponding to the number 11 in the sequence 1-11.
2 something occupying this position.
3 one of eleven equal parts of a thing.
4 Mus. a an interval or chord spanning an octave and a third in the diatonic scale. b a note separated from another by this interval.
--adj. that is the eleventh.
Phrases and idioms:
the eleventh hour the last possible moment.