Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
rē̆-trīmentum, i, n. [tero], the dregs, refuse, sediment of pressed olives, Varr. R. R. 1, 64; of metals, dross, Cels. 5, 15; 5, 19, 26; of food and drink, refuse, waste (i. e. excrement, urine), Varr. ap. Non. 217, 23; Macr. S. 7, 4; 7, 15.