noun, feminine/pɔʁ.sjɔ̃ kɔ̃.ɡʁy/plural: portions congrues
portion congrue is feminine in French.
part of the tithe (dîme) paid by the higher clergy (haut clergé) to the members of the lower clergy (bas clergé) for their sustenance; allowances of the lower clergy; tithe, trifling amount (the smallest share, the meanest share, the bare minimum - and possibly even less than that: barely enough)
“réduire à la portion congrue” — to minimize, to cut, to reduce to practically nothing