Antonyms of adj unceremonial

1 sense of unceremonial

Sense 1
unceremonious, unceremonial -- (without ceremony or formality; "an unceremonious speech")

INDIRECT (VIA informal) -> formal -- (being in accord with established forms and conventions and requirements (as e.g. of formal dress); "pay one's formal respects"; "formal dress"; "a formal ball"; "the requirement was only formal and often ignored"; "a formal education")

Similarity of adj unceremonial

1 sense of unceremonial

Sense 1
unceremonious, unceremonial -- (without ceremony or formality; "an unceremonious speech")
       => informal (vs. formal) -- (not formal; "conservative people unaccustomed to informal dress"; "an informal free-and-easy manner"; "an informal gathering of friends")