in-concessus — Lewis & Short
in-concessus, a, um, adj.,
I not allowed, impossible (not ante-Aug. and rare):
hymenaei,unlawful, forbidden, Verg. A. 1, 651; cf.
ignes,Ov. M. 10, 153:
spes,id. ib. 9, 638:
cum totum exprimere paene sit homini inconcessum,Quint. 10, 2, 26.