Meanings
- literarynot comparablevery quiet, almost inaudible
The noise of the ship was all around her. The faint subsonic rumble of the reactor and drive. (Leviathan Wakes, James S. A. Corey)
- not comparable(aviation) less than the speed of sound (in the same medium, and at the same temperature and pressure)
But British Airways Flight 112 made the trek in under five hours, setting a new record for the fastest subsonic commercial flight across the Atlantic Ocean.
2020 February 9, Alina Selyukh, “British Airways Sets Record, Crossing The Atlantic In Under 5 Hours In Strong Winds”, in NPR - not comparablefluid mechanicswith a Mach number such that 0.3 < Ma < 0.8 (approximately - the exact limits vary between sources)
Synonyms & antonyms
adjective(of speed) less than that of sound in a designated medium
Synonym sets from Open English WordNet, CC BY 4.0.
Origin
- Proto-Indo-European*upó
- Proto-Italic*supo
- Latinsub
- Latinsub-
- Englishsub-
- Proto-Indo-European*swenh₂-
- Proto-Indo-European*swónh₂os
- Latinsonus
- Englishsonic
- Englishsubsonic
Translations
Bulgarian дозвукова
- дозвукова(of a speed) less than the speed of sound
Chinese Mandarin 次音速
- 次音速 (cìyīnsù)(of a speed) less than the speed of sound
Czech podzvukový, subsonický
- podzvukový(of a speed) less than the speed of sound
- subsonický(of a speed) less than the speed of sound
Dutch subsonisch
- subsonisch(of a speed) less than the speed of sound
Finnish ääntä hitaampi, aliääni-
- ääntä hitaampi(of a speed) less than the speed of sound
- aliääni-(of a speed) less than the speed of sound
- aliääninen(of a speed) less than the speed of sound
- aliääninopeuksinen(of a speed) less than the speed of sound
French subsonique
- subsonique(of a speed) less than the speed of sound
Greek υποηχητικός
- υποηχητικός (ypoïchitikós)(of a speed) less than the speed of sound
Irish foshonach
- foshonach(of a speed) less than the speed of sound
Italian subsonico
- subsonico(of a speed) less than the speed of sound
Lithuanian ikigarsinis
- ikigarsinis(of a speed) less than the speed of sound
Polish poddźwiękowy
- poddźwiękowy(of a speed) less than the speed of sound
Portuguese subsónico, subsônico
- subsónico(of a speed) less than the speed of sound
- subsônico(of a speed) less than the speed of sound
Romanian subsonic
- subsonic(of a speed) less than the speed of sound
Russian дозвуково́й
- дозвуково́й (dozvukovój)(of a speed) less than the speed of sound
Spanish subsónico
- subsónico(of a speed) less than the speed of sound
Swedish subsonisk, underljuds-
- subsonisk(of a speed) less than the speed of sound
- underljuds-(of a speed) less than the speed of sound
Tagalog kubnugin
- kubnugin(of a speed) less than the speed of sound
Rhymes & wordplay
Rhymes with subsonic
Cite this entry
subsonic. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/subsonic
“subsonic.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/subsonic. Accessed November 3, 2026.
WatkinsX Dictionary, s.v. “subsonic,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/subsonic.
Source: subsonic on Wiktionary, CC BY-SA 4.0.