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

词根词缀：merci-

【来源及含义】Latin: merx, wares, merchandise

【同源单词】amerce, amerceable, commerce, commercial, commercialism, commercialization