Webster's Revised Unabridged Dictionary · 1913

Fourth

Fourth , adjective

[Old English fourthe, ferthe, feorthe, Anglo-Saxon feórea, from feówer four.]

1.
Next in order after the third; the ordinal of four.
2.
Forming one of four equal parts into which anything may be divided.

Fourth , noun

1.
One of four equal parts into which one whole may be divided; the quotient of a unit divided by four.
2.
(Music) The interval of two tones and a semitone, embracing four diatonic degrees of the scale; the subdominant of any key.
3.
One coming next in order after the third.
Collocations (1)
The Fourth , specifically, in the United States, the fourth day of July, the anniversary of the declaration of American independence; as, to celebrate the Fourth.