Thinner
Part of speech: adjective
Definition: Having little thickness or extent from one surface to its opposite.
Part of speech: noun
Definition: A liquid substance used to thin the consistency of another liquid.
Example sentence: I get more work when I'm thinner. I was playing Alice Cooper, and I had to lose a stone, so I wasn't eating sugar. You can't just get straight back onto sugar, as it's quite a powerful thing.
Diluent
Part of speech: noun
Definition: That which dilutes.A solvent or other liquid preparation used to dilute a sample prior to testing.An agent used for effecting dilution of the blood; a weak drink.
Part of speech: adjective
Definition: Diluting; making thinner or weaker by admixture, especially of water.