argill-, argillo- +

(Greek > Latin: clay)

argillous
Largely composed of, or containing, clay mineral or clay-size particles.

Cross references of word families related directly, or indirectly, to: "land, ground, fields, soil, dirt, mud, clay, earth (world)": agra-; agrest-; agri-; agro-; choro-; chthon-; epeiro-; geo-; glob-; lut-; myso-; pedo-; pel-; rhyp-; soil-; sord-; terr-.