The adjective antediluvian means someone or something that is extremely old-fashioned.
Synonyms are ancient, antique, old, or primitive.
The word origins in 1640s. It comes from Latin ante meaning “before” plus diluvium meaning “a flood”. It was coined by English physician Sir Thomas Browne (1605 – 1682). The noun meaning “person who levied before the flood” is from 1680s.
My teacher has some antediluvian ideas about the role of women.
There was humor about an antediluvian city ruled by intelligent reptiles.
The mean girls made her wear an antediluvian outfit at the party.