词根：tard = slow

  来自拉丁语的tardus意为slow。它的同义词根是slo,反义词根是来源于拉丁语celer的词根cel,celer意为swift。


同源词：

1. retard（因落后而慢re(=back) + tard(=slow)）
  vt.妨碍；拖延，推迟
  retardation n.妨碍；迟延，拖延
  Firefighters use certain chemicals that retard the spread of a fire.消防队员使用特定的化学物质阻止火势蔓延。

2. tardy
  adj.缓慢的，迟钝的；拖拉的；迟到的
  tardily adv.拖拖拉拉地，迟缓地
  tardiness n.缓慢；迟到
  tardy progress/repentance 缓慢的进展/迟来的后悔
  tardy in offering help 不情愿帮忙的
  be tardy for school上学迟到

词根：tard = slow, 表示“慢”

tardy a. 缓慢的，迟的

tardiness n. 拖拉（tardy的名词）

tardigrade a. 行动缓慢的（tard+I+grade步伐→步伐缓慢）

retard v. 延迟，妨碍（re一再+tard→一再慢下来→延迟）

词根词缀：nectar-

【来源及含义】Greek > Latin: drink of the gods; from Greek mythology

【相关词根词缀】 Related "drink" units: bib-; dipso-; haust-; poto-.

【同源单词】nectar, nectareal, nectarean, nectared, nectareous, nectarial

词根词缀：ptarmo-, ptarm-

【来源及含义】Greek: sneeze, a sneezing

【同源单词】aptarmia, ptarmia, ptarmic, Ptarmica, ptarmical, ptarmigenic

词根词缀：sidero-, sider- (star)

【来源及含义】Latin: star, stars

【相关描述】Don't confuse this element with another sidero- which means "iron".

【同源单词】consider, considerable, consideration, considered, considering, desiderata

词根词缀：tarax-, tarac-

【来源及含义】Greek > Latin: confusion, disturbance, irritation, trouble, lack of calmness

【同源单词】ataractic, ataraxia, ataraxy, taraxigenic, taraxigenous, taraxiphrenia

词根词缀：tard-

【来源及含义】Latin: slow; sluggish

【相关词根词缀】 Cross references directly, or partly, involving "slow, slowness, slow of, sluggish": dys-; lent-.

【同源单词】Ad vindictam tardus, aquitard, mental retardation, psychomotor retardation, psychosocial retardation, retard

词根词缀：tars-, tarso-

【来源及含义】Greek > Latin: ankle, tarsal plate of the eyelid; from Greek tarsos, frame of wickerwork; broad, flat surface, as also in tarsos podos, the flat of the foot, instep of the foot; the edge of the eyelid

【同源单词】blepharorrhaphy, digitometatarsal, ectrometatarsia, entometatarse, longitarsal, metatarsal

词根词缀：tetart-, tetarto-

【来源及含义】Greek: one fourth

【同源单词】tetartanopia, tetartanopic, tetartohedral, tetartohedron