What is the meaning of thinner?

noun

• A diluting agent.
  • synonyms: dilutant, diluent

adjective

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

adverb

• Without viscosity.
  • usage: "the blood was flowing thin"
  • synonyms: thinly, thin