Dictionary:

ceremonious

  (sĕr'ə-mō'nē-əs)

1. Strictly observant of or devoted to ceremony, ritual, or etiquette; punctilious: “borne on silvery trays by ceremonious world-weary waiters” (Financial Times).
2. 1. Characterized by ceremony.
   2. In accord with prescribed or customary usage; rigidly formal.

adjective

1. Fond of or given to ceremony: conventional, courtly, formal, punctilious. See courtesy/discourtesy.
2. Of or characterized by ceremony: ceremonial, formal, liturgical, ritual, ritualistic. See ritual.

Definition: ritual, formal
Antonyms: informal, relaxed, unceremonious, unobserved

The adjective has one meaning:

Meaning #1: rigidly formal or bound by convention
  Synonym: conventional

Common misspelling(s) of ceremonious

• cerimonious