From Longman Dictionary of Contemporary Englishninthninth1 /naɪnθ/ ●●● S3 W3 adjective HMNcoming after eight other things in a series in the ninth century her ninth birthday —ninth pronoun I’m planning to leave on the ninth (=ninth day of the month).
Examples from the Corpus
ninth• Sam is in ninth grade.on the ninth• The building was opened on the ninth anniversary of her death in 1862 and was for the consumptive poor.• Early on the ninth night, he tells us, the crucial healing dance began.ninthninth2 noun [countable] PARTone of nine equal parts of something 