IPA: //dʒuˈbɪl.ə.ri.ən//
KK: /dʒuˈbɪlɛrɪən/
A person who is celebrating a special anniversary or event, often related to a significant milestone such as a 25th or 50th anniversary.
The jubilarian was honored at the ceremony for reaching 50 years of service.
Jubilarian is derived from 'jubilaris' (meaning pertaining to a jubilee) and the suffix '-ian' (meaning relating to or characterized by). The word refers to a person who is celebrating a jubilee, often a significant anniversary or milestone.
Think of someone who is 'celebrating' ('jubilaris') a special anniversary — that's what a jubilarian is.