of ‧ fi ‧ ci ‧ ate /əˈfɪʃieɪt/ BrE AmE verb [intransitive]
[ Word Family: noun : ↑ office , ↑ officer , ↑ official , ↑ officialdom , ↑ officialese , ↑ officiousness ; adverb : ↑ officially ≠ ↑ unofficially , ↑ officiously ; adjective : ↑ official ≠ ↑ unofficial , ↑ officious ; verb : ↑ officiate ]
to perform official duties, especially at a religious ceremony