boycott

nouns

a group's refusal to have commercial dealings with some organization in protest against its policies
boycott
is a type of (narrower)
the act of protesting; a public (often organized) manifestation of dissent
dissent, objection, protest

verbs

refuse to sponsor; refuse to do business with
boycott
antonym
patronize
antonym
patronise
is a type of (narrower)
avoid speaking to or dealing with
"Ever since I spoke up, my colleagues ostracize me"
ostracise, ostracize