SWIFTNESS
speed, swiftness, fastness
(noun) a rate (usually rapid) at which something happens; “the project advanced with gratifying speed”
Source: WordNet® 3.1
Etymology
Noun
swiftness (usually uncountable, plural swiftnesses)
The state of being swift.
Synonyms
• celerity
• haste
• rapidity
Source: Wiktionary
Swift"ness, n.
Definition: The quality or state of being swift; speed; quickness;
celerity; velocity; rapidity; as, the swiftness of a bird; the
swiftness of a stream; swiftness of descent in a falling body;
swiftness of thought, etc.
Source: Webster’s Unabridged Dictionary 1913 Edition