1. a. : having little extent from one surface to its opposite. thin paper. b. : measuring little in cross section or diameter. thin rope. 2. : not dense in arrangement or distribution. thin hair. 3. : not well fleshed : lean. 4. a. : more fluid or rarefied than normal. thin air. b. : having less than the usual number : scanty. thin attendance. c. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.