amplitude modulation

n. Abbr. AM1. The encoding of a carrier wave by varying its amplitude in accordance with an input signal.2. A broadcast system that uses amplitude modulation.

amplitude modulation

n 1. (Telecommunications) one of the principal methods of transmitting audio, visual, or other types of information using radio waves, the relevant signal being superimposed onto a radio-frequency carrier wave. The frequency of the carrier wave remains unchanged but its amplitude is varied in accordance with the amplitude of the input signal. Abbreviation: AM or am Compare frequency modulation 2. (Telecommunications) a wave that has undergone this process

am

(æm; unstressed əm, m)

v. 1st pers. sing. pres. indic. of be. [before 900; Old English am, eam, eom]

AM

1. Asian male. 2. amplitude modulation: a method of impressing a signal on a radio carrier wave by varying its amplitude. 3. a system of broadcasting using this method. Compare FM. [1935–40]

Am

Chem. Symbol. americium.

Am.

1. America. 2. American.

A.M.

Master of Arts. [< Latin Artium Magister]

a.m.

or A.M.,

1. before noon. 2. the period from midnight to noon, esp. the period of daylight prior to noon. Compare p.m. [1755–65; < Latin ante merīdiem] usage: The abbreviation a.m. refers to the period from midnight until noon. One minute before noon is 11:59 a.m. One minute after noon is 12:01 p.m. Many people distinguish between noon and midnight by saying 12 noon and 12 midnight. Expressions such as 6 a.m. in the morning and 9 p.m. at night are redundant.