conventional
con-ven-tion-al
adjective
Following established customs and traditions; not new, original, or experimental.
"He preferred a conventional lifestyle over anything too adventurous."
Thesaurus
Synonyms: schematic, formal, nonrepresentational, orthodox, established, ceremonious, straight, stereotyped, buttoned-down, unimaginative, stereotypical, stereotypic
Antonyms: atomic, nuclear, unconventional