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：spin-, spino-, spini-

【来源及含义】Latin: thorn, prickle; by extension, "backbone", the spinal cord

【同源单词】anospinal, anterospinal, cerebrospinal, cervicispinal, costispinal, dorsispinal