Forewarn

(v. t.) To warn beforehand; to give previous warning, admonition, information, or notice to; to caution in advance.

Thesaurus Entries

apprehend, bode, caution, croak, forebode, give advance notice, have a premonition, have a presentiment, look black, lower, menace, portend, preapprehend, precaution, premonish, prenotify, prewarn, tell in advance, threaten, warn