1. n. [Geophysics]

An elastic body wave or sound wave in which particles oscillate in the direction the wave propagates. P-waves are the waves studied in conventional seismic data. P-waves incident on an interface at other than normal incidence can produce reflected and transmitted S-waves, in that case known as converted waves.

Synonyms: acoustic wave,  compressional wave,  dilatational wave

Antonyms: S-wave

See: body wave,  dilatation,  rarefaction,  shadow zone