What is the meaning of the word "thin"?

Definitions:

lacking excess flesh adjective
- You can't be too rich or too thin.
lacking spirit or sincere effort adjective
- Their thin smile hid something more sinister.
lacking substance or significance adjective
- Your argument is thin.
not very dense adjective
- They have thin beards.
of relatively small extent from one surface to the opposite or in cross section adjective
- I used a thin wire to tie the parts together.
of sound, lacking resonance or volume adjective
- The cat gave a thin feeble cry.
relatively thin in consistency or low in density adjective
- This grain is rather thin.
to lessen the strength or flavor of a solution or mixture verb
- We need to thin out this Bloody Mary mix a bit.
to lose thickness verb
- My hair is thinning.
to make thin or thinner verb
- We should thin out the herd.
to take off weight verb
- I am thinning nicely thanks to my new diet.
very narrow adjective
- I drew a thin line across the page.
without viscosity adverb
- The blood was flowing thin.