fourth
Americanadjective
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next after the third; being the ordinal number for four.
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being one of four equal parts.
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Automotive. of, relating to, or operating at the gear transmission ratio at which the drive shaft speed is greater than that of third gear for a given engine crankshaft speed, but not so great as that of fifth gear, if such exists.
fourth gear.
noun
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a fourth part, especially of one (¼).
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the fourth member of a series.
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Music.
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a tone on the fourth degree from a given tone (counted as the first).
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the interval between such tones.
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the harmonic combination of such tones.
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Automotive. fourth gear.
She downshifted from fifth to fourth as we started up the hill.
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the Fourth. Independence Day; the Fourth of July.
adverb
adjective
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coming after the third in order, position, time, etc. Often written: 4th
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( as noun )
the fourth in succession
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denoting the fourth forward ratio of a gearbox in motor vehicles
noun
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music
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the interval between one note and another four notes away from it counting inclusively along the diatonic scale
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one of two notes constituting such an interval in relation to the other See also perfect interval diminished
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the fourth forward ratio of a gearbox in a motor vehicle
he changed into fourth as soon as he had passed me
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a less common word for quarter
adverb
Other Word Forms
Noun Inflected Forms
Etymology
Origin of fourth
First recorded before 950; Middle English fourthe, Old English fēowertha; see four, -th 2
Vocabulary lists containing fourth
Measurement and Data
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Spelling Practice 1, Unit 3
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
In its finished version, Chasing Cars was released as the second single from Snow Patrol's fourth album, Eyes Open, in June 2006.
From BBC • Jul. 11, 2026
During its fourth integrated flight test, damage to its thermal protection system was severe enough that the design had to be substantially revised.
From Science Daily • Jul. 11, 2026
The agency’s fourth commissioner, Republican Donald Palmer, voluntarily departed the agency earlier this year to join the Heritage Foundation.
From Salon • Jul. 11, 2026
Thiero came back in the game in the fourth quarter and threw down another lob dunk.
From Los Angeles Times • Jul. 11, 2026
In the fourth generation, the hunt begins—and ends.
From "The Long-Lost Home" by Maryrose Wood
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.