Definitions
1.nounA mark or deformation of the ear of an animal, intended to indicate ownership.
2.nounThe designation of specific projects in appropriations of funding for general programs.
3.nounA mark for identification; a distinguishing mark.
4.verbTo mark (as of sheep) by slitting the ear.
5.verb(by extension) To specify or set aside for a particular purpose, to allocate."You can donate to the organization as a whole, or you can earmark your contribution for a particular project."