Transverse wave

From Glossary of Meteorology

transverse wave

A solenoidal plane wave A perpendicular to the propagation direction in the sense that if A = A0exp(ik · x - iωt), where k is the wave vector, then k × A = 0.

Electromagnetic waves are examples of transverse waves. Acoustic waves in solids have both irrotational and solenoidal components that propagate with different phase velocities.
Compare longitudinal wave.