Standard Lemma guide
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
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adj
having a frequency too low to be audible
Definition source: English Wiktionary via Wiktextract
Usage: not-comparable
Topics: sciences, scientific
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
adj
very quiet, almost inaudible
Definition source: English Wiktionary via Wiktextract
Usage: literary, not-comparable
Synonyms: none provided
Antonyms: none provided
adj
(aviation) less than the speed of sound (in the same medium, and at the same temperature and pressure)
Definition source: English Wiktionary via Wiktextract
Usage: not-comparable
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
adj
with a Mach number such that 0.3 < Ma < 0.8 (approximately - the exact limits vary between sources)
Definition source: English Wiktionary via Wiktextract
Usage: not-comparable
Qualifier: fluid mechanics
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
noun
an aircraft whose maximum speed is less than the speed of sound
Definition source: English Wiktionary via Wiktextract
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
adjective
(of speed) less than that of sound in a designated medium
Definition source: Princeton WordNet 3.0
Synonyms: none provided
Antonyms: sonic, supersonic
History
Etymology tree Proto-Indo-European *upó Proto-Italic *supo Latin sub Latin sub-der. English sub- Proto-Indo-European *swenh2- Proto-Indo-European *swónh2os Latin sonus Proto-Indo-European *-ikos Proto-Italic *-ikos Latin -icuslbor. Old French -iquebor. Middle English -ik English -ic English sonic English subsonic From sub- + sonic.
Across languages
23 source translations are retained for this English entry.
