pro·hib·i·tive 
(prō-hĭbĭ-tĭv) also pro·hib·i·to·ry (-tôr′ē)
(prō-hĭbĭ-tĭv) also pro·hib·i·to·ry (-tôr′ē)adj.
1. Prohibiting; forbidding: took prohibitive measures.
2. So high or burdensome as to discourage purchase or use: prohibitive prices.
3. So likely to win as to discourage competition: the prohibitive favorite to win the nomination.
pro·hibi·tive·ly adv.
pro·hibi·tive·ness n.