Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
cŏ-hēres (-haeres), ēdis, comm., a coheir, fellow-heir, Cic. Verr. 2, 1, 48, § 127; id. Fam. 13, 46 init.; 7, 2, 1; Quint. 5, 14, 16.
Gen. plur. coheredum, Hor. S. 2, 5, 107: esse coheres alicui, id. ib. 2, 5, 54; Petr. 76, 2.
In the fem., Dig. 34, 9, 16.