Wiktionary
doubleth
vb. (context archaic English) (en-third-person singular of: double)
Usage examples of "doubleth".
Diabolus having thus armed and forearmed his servants and vassals in Mansoul against their good and lawful King Shaddai, in the next place, he doubleth his guards at the gates of the town, and he takes himself to the castle, which was his stronghold.
As the accompt of the Assis ariseth, and coming at the last unto Usura ex asse, it amounteth to twelve in the hundred, and therefore the Latins call it Centesima, for that in the hundred month it doubleth the principal.