The Collaborative International Dictionary of English v.0.48:
Forth \Forth\, v.[AS. for[eth], fr. for akin to D. voort, G.
fort [root]78. See Fore, For, and cf. Afford,
1. Forward; onward in time, place, or order; in advance from
a given point; on to end; as, from that day forth; one,
two, three, and so forth.
Lucas was Paul's companion, at the leastway from the
sixteenth of the Acts forth. --Tyndale.
From this time forth, I never will speak word.
I repeated the Ave Maria; the inquisitor bad me say
forth; I said I was taught no more. --Strype.
2. Out, as from a state of concealment, retirement,
confinement, nondevelopment, or the like; out into notice
or view; as, the plants in spring put forth leaves.
When winter past, and summer scarce begun,
Invites them forth to labor in the sun. --Dryden.
3. Beyond a (certain) boundary; away; abroad; out.
I have no mind of feasting forth to-night. --Shak.
4. Throughly; from beginning to end. [Obs.] --Shak.
And so forth, Back and forth, From forth. See under
And, Back, and From.
Forth of, Forth from, out of. [Obs.] --Shak.
To bring forth. See under Bring.