(1):
(n.) 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.
(2):
(n.) Intimation of caution; warning; protest.
(3):
(n.) 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.