Is it ensure, insure, or assure?
1755, from Late Latin trituratus, past participle of triturare "to thresh, to grind," from Latin tritura "a rubbing, a threshing," from past participle stem of terere "to rub" (see throw). Related: Triturated; triturating.
triturate trit·u·rate (trĭch'ə-rāt')
v. trit·u·rat·ed, trit·u·rat·ing, trit·u·rates
To rub, crush, grind, or pound into fine particles or a powder. n.
A triturated substance, especially a powdered drug.