cotton             
noun [ U ] uk/ˈkɒt.ən/ us/ˈkɑː.t̬ən/
 棉,棉花
the threads that grow around the seeds of a tall plant grown especially in the US, China, and South Asia
  a bale of cotton 一大包棉花 
 B1 棉线;棉布
thread or cloth made from the fibres of the cotton plant
  a shirt made of pure cotton 纯棉衬衫 
 She looked pretty in a simple cotton dress. 她穿着朴素的棉布连衣裙,看上去很漂亮。 
UK a reel of cotton (= thread) 一卷棉线 
  US or Indian English (UK cotton wool)(通常用于清洁皮肤的)药棉,脱脂棉 
cotton in the form of a soft mass, usually used for cleaning your skin
  cotton pads 化妆棉 
 - More examples
 - Natural fibres such as cotton tend to be cooler.
 - A sweater knitted in pure cotton hasn't much give .
 - He shivered with cold in his thin cotton shirt.
 - Black slaves used to work on the cotton plantations of the southern United States.
 - The final stage of the production of cotton is when it is spun into thread.