Wiktionary’s definition of boycott: To abstain, either as an individual or group, from using, buying, or dealing with someone or some organization as an expression of protest.
Google definition: withdraw from commercial or social relations with (a country, organization, or person) as a punishment or protest.
Dictionary .com definition: to combine in abstaining from, or preventing dealings with, as a means of intimidation or coercion: “to boycott a store.”