1. 理解：cotton mill 纱厂 | cotton on 理解 | cotton paper 棉纸
2. 领会：cotton on to 领会 | cotton on 领会 | decide 决定
1. 明白;领悟;意识到
If you cotton on to something, you understand it or realize it, especially without people telling you about it.
e.g. She had already cottoned on to the fact that the nanny was not all she appeared...
她已经意识到这个保姆不只是她看起来的那样。
e.g. It wasn't until he started laughing that they cottoned on!
他开始笑起来，他们才明白是怎么回事。