The Collaborative International Dictionary of English v.0.48:
Warrantise \War"rant*ise\, n. [OF. warentise, warandise, garantise. See Warrant, n.] Authority; security; warranty. [Obs.] --Shak. [1913 Webster]The Collaborative International Dictionary of English v.0.48:
Warrantise \War"rant*ise\, v. t. To warrant. [Obs.] --Hakluyt. [1913 Webster]