I. noun — [ mass noun] 1.
[Physics] the maximum extent of a vibration or oscillation, measured from the position of equilibrium.
• the amplitude of alpha rhythms.
• [ count noun]
waves with amplitudes greater than or equal to 20 mm.
2. the maximum difference of an alternating electric current or potential from the average value. • the detection of signals only a few microvolts in amplitude.
[Astronomy] the angular distance of a celestial object from the true east or west point of the horizon at rising or setting.
4. breadth, range, or magnitude • the amplitude of the crime of manslaughter lies beneath murder.
[Mathematics] the angle between the real axis of an Argand diagram and a vector representing a complex number.
– origin mid 16th cent. (in the senses ‘physical extent’ and ‘grandeur’): from Latin amplitudo, from amplus ‘large, abundant’.