amplitude

UK: /ˈæmplɪtjuːd/

US: /ˈæmplɪˌtud, -ˌtjud/

US: (am′pli to̅o̅d′, -tyo̅o̅d′)

WordReference Random House Learner's Dictionary of American English © 2026

am•pli•tude /ˈæmplɪˌtud, -ˌtyud/   n. [uncountable]

1. the state or quality of being ample;
   fullness;
   largeness.
2. large or full measure;
   abundance.

See -ampl-.

WordReference Random House Unabridged Dictionary of American English © 2026

am•pli•tude  (am′pli to̅o̅d′, -tyo̅o̅d′), n. 

1. the state or quality of being ample, esp. as to breadth or width;
   largeness;
   greatness of extent.
2. large or full measure;
   abundance;
   copiousness.
3. mental range, scope, or capacity.
4. Physics the absolute value of the maximum displacement from a zero value during one period of an oscillation.
5. Electricity the maximum deviation of an alternating current from its average value.
6. Astronomy the arc of the horizon measured from the east or west point to the point where a vertical circle through a heavenly body would intersect the horizon.
7. Mathematics argument (def. 8b).

• Latin amplitūdō. See ample, -i-, -tude
• 1540–50

Collins Concise English Dictionary © HarperCollins Publishers::

amplitude / ˈæmplɪˌtjuːd/ noun

1. greatness of extent; magnitude
2. abundance or copiousness
3. breadth or scope, as of the mind
4. the angular distance along the horizon measured from true east or west to the point of intersection of the vertical circle passing through a celestial body
5. (of a complex number) the angle that the vector representing the complex number makes with the positive real axis. If the point (x, y) has polar coordinates (r, θ), the amplitude of x + iy is θ, that is, arctan y/x
   Compare modulus2
6. the maximum variation from the zero or mean value of a periodically varying quantity

Etymology: 16th Century: from Latin amplitūdō breadth, from amplus spacious