Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
* post-gĕnĭtus, or separate, post gĕnĭtus, a, um, adj., born afterwards; in plur. subst.: postgĕnĭti, ōrum, m., posterity, descendants (poet.), Hor. C. 3, 24, 30.