(philosophy) An ontological position stating that an object's persistence through time is like its extension through space.

(historical) The four traditional things targeted for destruction during China's Cultural Revolution, usually translated as old customs, old culture, old habits, and old ideas.

off-roading in a vehicle with four-wheel drive

(poker) The rule of multiplying the number of outs by four to discover one's approximate chance to make one's hand on the turn or river. Compare rule of two.

plural of four-peat

plural of four-flusher

plural of four-flush

plural of four-velocity

plural of four-speed

plural of four-o'clock