Early 17th century; earliest use found in George Abbot (1562–1633), archbishop of Canterbury. From classical Latin celebris, variant of celeber célèbre + -ous; compare alacrious.
Definition of celebrious in US English:
celebrious
adjectivesɪˈlɛbrɪəs
rare
Famous, well-known, renowned.
Origin
Early 17th century; earliest use found in George Abbot (1562–1633), archbishop of Canterbury. From classical Latin celebris, variant of celeber célèbre + -ous; compare alacrious.