thin in WordNet English dictionary

1. lessen the strength or flavor of a solution or mixture
   "cut bourbon"
   dilute  thin  thin out  reduce  cut 
   
2. take off weight
   reduce  melt off  lose weight  slim  slenderize  thin  slim down 
   
3. lose thickness; become thin or thinner
   thin 
   
4. make thin or thinner
   "Thin the solution"
   thin 
   

1. lacking substance or significance
   "slight evidence"; "a tenuous argument"; "a thin plot"; a fragile claim to fame"
   flimsy  fragile  slight  tenuous  thin 
   
2. lacking excess flesh
   "you can't be too rich or too thin"; "Yon Cassius has a lean and hungry look"-Shakespeare
   thin  lean 
   
3. very narrow
   "a thin line across the page"
   slender  thin 
   
4. not dense
   "a thin beard"; "trees were sparse"
   sparse  thin 
   
5. of relatively small extent from one surface to the opposite or in cross section
   "thin wire"; "a thin chiffon blouse"; "a thin book"; "a thin layer of paint"
   thin 
   
6. relatively thin in consistency or low in density; not viscous
   "air is thin at high altitudes"; "a thin soup"; "skimmed milk is much thinner than whole milk"; "thin oil"
   thin 
   
7. (of sound) lacking resonance or volume
   "a thin feeble cry"
   thin 
   
8. lacking spirit or sincere effort
   "a thin smile"
   thin 
   

1. without viscosity
   "the blood was flowing thin"
   thinly  thin  thinly  thin