Collectively, peoples living nomadic, pastoral, hunter-gatherer or other ways of life outside the modern industrial norm.

(algebraic geometry) The fourth coordinate indicating a position along the fourth axis. / (physics) The dimension of time.

At the fourth level of some system, particularly: / (of burns) The most severe level of damage, typically involving major damage to muscles, tendons, and ligaments as well as the skin.

(music) A musical interval of the Western twelve-semitone system consisting of four semitones and spanning four degrees of the diatonic scale. It is one semitone narrower than a perfect fourth and enharmonically equivalent to a major third.

(music) A type of tritone in musical composition comprising six semitones. It spans four diatonic scale degrees like a perfect fourth but with an extension of a semitone. The number of diatonic degrees it spans is what distinguishes it from a diminished fifth.

plural of fourth official

plural of twenty-fourth

plural of fourth slip

plural of augmented fourth

plural of diminished fourth