from
The Collaborative International Dictionary of English v.0.48
Fourth \Fourth\, n.
1. One of four equal parts into which one whole may be
divided; the quotient of a unit divided by four.
[1913 Webster]
2. (Mus.) The interval of two tones and a semitone, embracing
four diatonic degrees of the scale; the subdominant of any
key.
[1913 Webster]
3. One coming next in order after the third.
[1913 Webster]
{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.
[1913 Webster]