Is it ensure, insure, or assure?
mid-14c., "real, ordinary; earthly, drawn from the material world;" a term in scholastic philosophy and theology, from Old French material, materiel (14c.) and directly from Late Latin materialis (adj.) "of or belonging to matter," from Latin materia "matter, stuff, wood, timber" (see matter). From late 14c. as "made of matter, having material existence; material, physical, substantial;" from late 15c. as "important, relevant."
late 14c., "substance, matter from which a thing is made," from material (adj.).