词根词缀：fac-, facil-, fact-, feas-, -feat, -fect, -feit, -facient, -faction, -fic-, -fy, -ficate, -fication

【来源及含义】Latin: to make, to do, to build, to cause, to produce; forming, shaping

【同源单词】Ab officio et beneficio, abortifacient, absorbefacient, absorbifacient, acoustoelectric effect, affair

词根词缀：-less

【来源及含义】Old English: -leas, from leas, "free from, devoid of, false, feigned"; suffix meaning "lacking"

【同源单词】aimless, artless, avoidless, causeless, ceaseless, charmless