inaugural
n.n. marking the very first time an event or activity happens. You use this to describe something official, like the first meeting of a group or the first day of a new leader's job.
n. marking the beginning of an institution, activity, or period of office. Often used in formal contexts to describe first-time ceremonies or events.
She gave a speech at the inaugural meeting.
The city hosted its inaugural film festival last summer, drawing thousands of visitors to the downtown area.
The president's inaugural address focused on national unity and economic recovery, setting a hopeful tone for the administration's first hundred days in office.
From French inaugural, from inaugurer, from Latin augurare (“to take omens”).
Typically placed before the noun it modifies; frequently collocates with 'address', 'meeting', 'event', or 'season'.