非法

illegal; unlawful; illicit; illegitimate; unauthorized; outlawed; shady; under-the-counter; unrecognized; improper; unorthodox; lawless; banned; forbidden; bandy around; hold ground; illegalize; criminalize; outlaw; ban; prohibit; on the side; under the counter

渠道

channel; conduit; canal; route; ditch; watercourse; irrigation ditch; medium of communication; a window into; a window on