Adjective fourth has 1 sense
- fourth, 4th, quaternary - coming next after the third and just before the fifth in position or time or degree or magnitude; "the quaternary period of geologic time extends from the end of the tertiary period to the present"
Antonym: cardinal (indirect, via ordinal)
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Adverbial fourth has 1 sense
- fourthly, fourth - in the fourth place; "fourthly, you must pay the rent on the first of the month"
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Noun fourth has 3 senses
- fourth - following the third position; number four in a countable series
--1 is a kind of rank
- one-fourth, fourth, quarter, fourth part, twenty-five percent, quartern - one of four equal parts; "a quarter of a pound"
--2 is a kind of common fraction, simple fraction
- fourth - the musical interval between one note and another four notes away from it
--3 is a kind of interval, musical interval
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