office A1

/ˈɔ.fɪs/ a religious rite or service prescribed by ecclesiastical authorities

officer A1

/ˈɒf.ə.sə/ any person in the armed services who holds a position of authority or command

official A2

/əˈfɪʃəl/ having official authority or sanction

opera A1

/ˈɑp.ə.ɹə/ A building designed for the performance of such works; an opera house.

operate A2

/ˈɑpəɹeɪt/ perform surgery on

operator B2

/ˈɑpəˌɹeɪtɚ/ an agent that operates some apparatus or machine

opulent C2

/ˈɒpjʊlənt/ Luxuriant, and ostentatiously magnificent.

opulence C2

/ˈɒp.jʊl.əns/ Ostentatious display of wealth and luxury; plushness.