silentyoudaoicibaDictYouDict[silent 词源字典]
silent: [16] Silent comes from the present participle of Latin silēre ‘be silent’. It is not clear what the origins of this were, although it seems likely to be related in some way to Gothic anasilan, a verb which denoted the wind dying down, and also perhaps to Latin dēsinere ‘stop’ (in which case its underlying meaning would be ‘stop speaking’). The Latin-derived noun silentium actually reached English much earlier than the adjective, as silence [13].
[silent etymology, silent origin, 英语词源]
silent (adj.)youdaoicibaDictYouDict
c. 1500, "without speech, silent, not speaking," from Latin silentem (nominative silens) "still, calm, quiet," present participle of silere "be quiet or still" (see silence (n.)). Meaning "free from noise or sound" is from 1580s.

Of letters, c. 1600; of films, 1914. In the looser sense "of few words," from 1840. Phrase strong, silent (type) is attested from 1905. Silent majority in the political sense of "mass of people whose moderate views are not publicly expressed and thus overlooked" is first attested 1955 in a British context and was used by John F. Kennedy but is most associated in U.S. with the rhetoric of the Nixon administration (1969-74).
It is time for America's silent majority to stand up for its rights, and let us remember the American majority includes every minority. America's silent majority is bewildered by irrational protest. [Spiro T. Agnew, May 9, 1969]
In Victorian use, the phrase meant "the dead" (1874; compare Roman use of the noun plural of "silent" to mean "the dead"). Silence is golden (1831) is Carlyle's translation ["Sartor Resartus"] of part of the "Swiss Inscription" Sprechen ist silbern, Schweigen ist golden. In one 14c. text Latin "one who is silent" is translated by a beere stille.