Definitions

1. adjective

belonging to or characteristic of an early stage in the development of something

“The writer used archaic language in her novel to create an old-fashioned atmosphere.”

2. noun

something that is out of date or no longer used

“The archaic computer system was replaced with a newer one for better efficiency.”

3. noun

a word or expression that is no longer used in modern language

“The archaic term ‘thou’ is rarely used in everyday conversation.”