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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noun
speed, swiftness; the condition of being rapid
Definition source: English Wiktionary via Wiktextract
Usage: countable, uncountable
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
noun
A measure of velocity relative to the speed of light; defined as artanh(v), where artanh is the hyperbolic arctangent, and v = speed (with c = speed of light = 1).
Definition source: English Wiktionary via Wiktextract
Usage: countable, uncountable
Qualifier: relativity
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
noun
A measure of the velocity of a particle in a beam relative to the beam's axis
Definition source: English Wiktionary via Wiktextract
Usage: countable, uncountable
Topics: natural-sciences, physical-sciences, physics
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
noun
a rate that is rapid
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Synonyms: celerity, quickness, rapidness, speediness
Antonyms: none provided
Broader terms: pace, rate
Narrower terms: fleetness, immediacy, immediateness, instantaneousness, instancy, dispatch, despatch, expedition, expeditiousness, promptness, promptitude
History
From rapid + -ity, from French rapidité, from Latin rapiditas.
Across languages
19 source translations are retained for this English entry.
