"Caveat" is a word in LAW AND LEGAL, ENGLISH

Lat Let him beware. A formal notice or warning given by a party ln-terested to a court, judge, or ministerial offl-cer against tbe performance of certain acts within his power and jurisdiction. This process may be used ln the proper courts to pre-vent (temporarily or provisionally) the prov-lng of a will or the grant of admlnistration, or to arrest the enrollment of a decree ln chancery when the party Intends to take an appeal, to prevent the grant of letters patent, etc. It ls also used, in the American prac-tlce, as a kind of equitable process, to stay the granting of a patent for lauds, wilson v. Gaston, 92 Pa. 207; Slocum v. Grandin, 38 N. J. Eq. 485; Ex parte Crafts, 28 S. C. 281, 6 S. E. 718; In re Miller's Estate, 166 Pa. 97, 81 Atl. 58

Intimation of caution; warning; protest.

A description of some invention, designed to be patented,
lodged in the patent office before the patent right is applied for, and
operating as a bar to the issue of letters patent to any other person,
respecting the same invention.

A notice given by an interested party to some officer not
to do a certain act until the party is heard in opposition; as, a
caveat entered in a probate court to stop the proving of a will or the
taking out of letters of administration, etc.