The ninth remove in the chain of kinship; especially the ninth generation of descent from a particular individual. Also (in extended use, especially with to): the greatest possible extent; the maximum degree.
Origin
Late Middle English; earliest use found in Henry Lovelich (fl. 1450), poet. From ninth + degree.
Definition of ninth degree in US English:
ninth degree
nounˌnʌɪnθ dɪˈɡriː
The ninth remove in the chain of kinship; especially the ninth generation of descent from a particular individual. Also (in extended use, especially with to): the greatest possible extent; the maximum degree.
Origin
Late Middle English; earliest use found in Henry Lovelich (fl. 1450), poet. From ninth + degree.