-ant — one who, a thing that, (adj.) performing (affix)

assistant A2

/əˈsɪstənt/ A person whose job is to help someone, especially in their work.

servant B1

/ˈsɝvənt/ A person employed to do household or other duties for another, especially in someone's home.

defendant B2

/dɪˈfɛndənt/ a person or organization accused of a crime in a court case

accountant B1

/əˈkaʊn.tənt/ A person whose job is to keep, check, and report on money records for a person or business.

applicant B2

/ˈæp.lə.kɪnt/ A person who formally asks for something such as a job, a place at a school, or admission.