犯困fànkùnTop 50000Meanings1. (coll.) to get sleepyCharacters used犯to violate困to surroundExamples1不bù知道zhīdào为什么wèishénme我wǒ一yī开始kāishǐ学习xuéxí就jiù会huì犯困fànkùn。For some reason, I feel sleepy when I start studying.