What is Thin ?
Thin is (adj) 1. not fat The table has very thin legs. He’s too thin he should eat more. as thin as a rake very thin She’s a supermodel and is as thin as a rake. 2. not thick a plate of thin sandwiches The book is printed on very thin paper. The parcel was sent in a thin cardboard box. 3. not placed or growing close together The hill was covered with thin grass. The audience is a bit thin tonight. 4. (of a liquid.) which flows easily, which has too much water All we had for lunch was a bowl of thin soup. Add water to make the paint thinner. 5. which you can see through They hung thin curtains in the windows. A thin mist covered the valley. 6. (of an argument or excuse) weak or poor His argument is a bit thin. (NOTE: thinner thinnest) (adv) thinly Don’t spread the butter too thin. (verb) 1. to make something more liquid If you want to thin the soup just add some water. 2. to become fewer The crowds began to thin by evening. 3. to thin out to make plants grow less close together These lettuces need to be thinned out.
source: Easier English, Student Dictionary Upper Intermediate Level