Noah Webster's New International Dictionary of the English Language

1. (n.) A careful attention to the probable effects of an act, in order that failure or harm may be avoided; prudence in regard to danger; provident care; wariness.

2. (n.) Security; guaranty; bail.

3. (n.) Precept or warning against evil of any kind; exhortation to wariness; advice; injunction.

4. (v. t.) To give notice of danger to; to warn; to exhort [one] to take heed.