What is another word for "preemption"?

Roget's Thesaurus (1911) lists these synonyms for "preemption": always, bribe, bribery, buy, buyer, caveat, client, clientele, coemption, complete, counter, customer, employer, emption, hire, invest, keep, make, market, over, patron, pay, procure, purchase, purchaser, refusal, rent, repurchase, right, shop, slave, spend, suborn, the, trade, vendee.