verb

withdraw from commercial or social relations with (a country, organization, or person) as a punishment or protest.

we will boycott all banks which take part in the loans scheme

spurn,snub,cold-shoulder,shun,avoid,abstain from,stay away from,steer clear of,give a wide berth to,refuse to take part in,turn one’s back on,have nothing to do with,wash one’s hands of,ban,bar,reject,veto,embargo,place an embargo on,prohibit,debar,outlaw,proscribe,interdict,blackball,blacklist,black

noun

a punitive ban on relations with other bodies, cooperation with a policy, or the handling of goods.

a boycott of the negotiations

ban,bar,veto,embargo,moratorium,prohibition,proscription,interdict,injunction,sanction,restriction,barrier,avoidance,shunning,rejection,refusal,thumbs down,red light,knock-back