maximum extent of vibration measured from position of equlibrum  

highest point of a wave 

a measurement of how tall a person or thing is : the distance from the bottom to the top of a person or thing.  

distance between two corresponding points of a wave. For example (0,2pi) 

number of times per second that a wave cycles

a force that tends to produce an elongation of a body or structure.

 distance traversed by a periodic, or cyclic, motion per unit time.

single vibratory disturbance that moves from point to point.