"be silent," 1560s, from a verb mum (Middle English mommen) "make silent" (c. 1400); "be silent" (mid-15c.), from mum, mom (late 14c.), "an inarticulate closed-mouth sound" indicative of unwillingness or inability to speak, probably imitative. As an adjective meaning "secret" or "silent" from 1520s. Phrase mum's the word is recorded by 1704.
1560s, intransitive, "become still or silent;" 1590s, transitive, "make silent, restrain from speech or noise," from silence (n.). Related: Silenced; silencing.
"motion picture with sound," 1913, from earlier talking picture (1908), from talk (v.).
"avoidance of saying too much or speaking too freely," c. 1600, from French réticence (16c.), from Latin reticentia "silence, a keeping silent," from present participle stem of reticere "keep silent," from re-, here perhaps intensive (see re-), + tacere "be silent" (see tacit). "Not in common use until after 1830" [OED]. Related: Reticency.
rhetorical artifice wherein the speaker suddenly breaks off in the middle of a sentence, 1570s, from Latin, from Greek aposiōpesis "a becoming silent," also "rhetorical figure of breaking off," from aposiōpan "become silent," from apo "off, away" (see apo-) + siōpē "silence," which is perhaps from a PIE *swī- "to be silent," but Beekes suspects it is Pre-Greek (non-IE). Related: Aposiopetic.
"noise, what is heard, sensation produced through the ear," late 13c., soun, from Old French son "sound, musical note, voice," from Latin sonus "sound, a noise," from PIE *swon-o-, from root *swen- "to sound."
The unetymological -d was established c. 1350-1550 as part of a tendency to add -d- after -n-. Compare gender (n.), thunder (n.), jaundice (n.), spindle, kindred, riband, and, from French powder (n.), meddle, tender (adj.), remainder, dialectal rundel, rundle for runnel, etc. First record of sound barrier is from 1939. Sound check is from 1977; sound effect is 1909, originally live accompaniment to silent films.
The experts of Victor ... will ... arrange for the synchronized orchestration and sound effects for this picture, in which airplane battles will have an important part. [Exhibitor's Herald & Moving Picture World, April 28, 1928]
by 1884 as a colloquial shortening of picture (n.). Short for motion picture by 1936. Even more colloquial piccy is recorded from 1889.
"ornamental border of a picture," 1864 from verbal derivative of mat (n.2).
exclamation commanding silence, 1610s. Probably because the sound is both easy to hear and suddenly silent.
