the largest value of the displacement from equilibrium of an oscillation

a point in a medium with a standing wave where the displacement is momentarily a maximum

a point in a medium through which a wave is travelling that has maximum density

the superposition of two identical waves that arrive at a point in phase

a point on a wave of maximum displacement

the angle of incidence for which the angle of refraction is a right angle

the superposition of two identical waves that arrive at a point 180^o out of phase

the spreading of a wave past an aperture or an obstacle

a series of very many and narrow slits

the dependence of refractive index on wavelength