PROPER Synonyms: 218 Similar and Opposite Words - Merriam-Webster
https://www.merriam-webster.com/thesaurus/proper
WEBSynonyms for PROPER: polite, satisfactory, respectable, correct, acceptable, decorous, nice, adequate; Antonyms of PROPER: improper, inappropriate, incorrect, unsatisfactory, indecent, unseemly, unacceptable, informal.
DA: 84 PA: 59 MOZ Rank: 88