1. A journalist or writer who regularly writes a column for a newspaper, magazine, or online publication
The political columnist writes about current events every Monday.
O colunista político escreve sobre acontecimentos atuais toda segunda-feira.
2. A person who contributes regular opinion pieces or commentary to a publication
She is a renowned sports columnist for the major newspaper.
Ela é uma renomada colunista de esportes do jornal maior.