Real Dictionary

boycott
verb: If a country, group, or person boycotts a country, organization, or activity, they refuse to be involved with it in any way because they disapprove of it.

boycott in American English
to join together in refusing to deal with, so as to punish, coerce, etc.
noun: the practice of boycotting
transitive verb: to combine in abstaining from, or preventing dealings with, as a means of intimidation or coercion

boycott in British English
noun: an instance or the use of boycotting
noun: Sir Geoff(rey). born 1940, English cricketer: played for Yorkshire (1962–86); played in 108 test matches (1964–82); first England batsman to score 8,000 test runs
verb: to refuse to have dealings with (a person, organization, etc) or refuse to buy (a product) as a protest or means of coercion