IPA: /ˈnaɪnθli/
KK: /naɪnθli/
In the ninth position or order; used to indicate something that comes after eight others.
She finished ninthly in the race, just behind her friend.
Ninthly → It is formed from "ninth" (from Old English "nīoþa", meaning the ordinal number for nine) and "-ly" (meaning in a manner of). The word "ninthly" means in the manner of the ninth item or point.
Think of the word 'ninth' which refers to the number nine, and remember that 'ninthly' describes something done in the manner of the ninth point.