DictionaryrareLow density
adjective

rare

Thin or low in density.

The old scientific text describes the air as rare at that height.

Etymology

Latin rarus means loose, scattered, or thin. The physical sense preserves low concentration of material rather than the more familiar low frequency of events.

More examples

  • The experiment compared rare and dense gases.
  • The air became rarer as pressure fell.
  • She studied the behavior of matter in a rare state.

Forms

rare · rarer · rarest

Similar words

thin
Low in density or concentration.
rarefied
Made less dense, especially of a gas.