词根:sid(sed, sit), sess(sid) = to sit 坐

  词根sid来源于拉丁语的不定式词干 sidere,词根sess来自动名词词干,都意为to sit(坐)或to settle(安定)。sid为元音弱化后形成的词根。sid,sess属于一对同源异形根,反义词根有来自拉丁语的st,stat,stit,sist等。

同源词:

1. assiduous [一直坐着的as<ad(=to,intensive)+sid(=sit)]
  adj.“constant or unwearied in application; diligent 刻苦的;勤奋的:He is assiduous in his study 他学习勤奋。
    assiduity [as-; sid;-u-;-ity n.]n.刻苦;勤奋

2. preside  [before前;sid= to sit 坐;-e- “to sit before others 坐在其他人前面”]  v. sit in authority; act as chairman 主持;作会议主席:
    to preside at a meeting  主持会议
    presider  n.(会议的)主席;主持者
    presidium  n.主席团;常务委员会

3. president  v.主持,当权;-ent n.= person 人 →] 
  n.person chosen to preside over a nation. university or any other organization  总统;大学校长:会长:社长等
    presidency  n. 总统等的职位或任期
    presidential adj. 总统(或校长等)的

4. reside [re-= back,down 回,下;sid = to sit or settle 坐,安放:-e → "to sit backward, to settle down 靠背安坐,安顿下来” →]
  v. make one's home at a place 安家,居住:to reside in the city  在城市居住
    resident n. 居民
    residence n. 居住;住宅

5. subside [sub- = under,down下;sid= to sit or settle 坐,停留:-e →“to settle down 停在下面,停息”→]
  v. ①sink down 下沉;沉降:The building subsides gradually. 这座房子逐渐下沉。
     ②fall into a state of quiet 平息:The wind has subsided  风停了。
     subsidence  n.下降;沉降;平息

6. dissident [dis-= apart 分开;sid= to sit 坐;-ent  n. = person 人世间→ "person who sits apart from others 与别人分开坐的人”→]
  n. person openly disagreeing with an opinion; dissenter  持异议者;反对者:political dissidents  持不同政见者
     dissidence [dis-; sid; -ence n.]  n. 异议;不一致

7. insidious [in- = in 内;sid= to sit 坐;-i-; -ous adj. = like 像……的_→ "like sitting in a hidden place,like setting an ambush 像坐在暗处的,像打埋伏的”→]
  adj. ① intended to entrap 伺机为害的:insidious diseases 暗疾
       ②deceptive; treacherous 暗中为害的;阴险的:an insidious tempter 阴险的诱惑者
      insidiousness  n. 阴险;狡诈

8. session [sess= to sit 坐;-ion n. = the act or state 表行为或状态 →]
  n. ① act of sitting 坐;就座
     ②sitting or time of sitting, as of a court or public body 开会;开庭;会期;开庭期:plenary session 全体会议
      sessional  adj. 开会的;开庭的

9. possess [pos(来自potis) = able 能……的;sess= to sit 坐→ "to be able to sit in a place 能坐在一个位置上”→]
  v. ① inhabit or occupy 居住于;占据
     ② have or hold as property own 具有;占有:He possessed landed property 他拥有地产。
     ③ maintain or control 保持;控制:She was possessed by the desire to be rich  她被发财的欲望所支配。
     possessor [possess; -or n.] n.占有人;所有人
     possession [possess;-ion n.] n.占有;占有物;财产;领地
     possessive [possess; -ive adj.] adj. 占有的 n.[语法]所有格

10. assess [as-(ad-) = to,at在;sess= to sit坐→“(judges in a court) to sit at or sit by(法官等在法庭)就座”→ "to judge or estimate 作判断,估计”→]
  v. ①fix the value or profits of 对……进行估价:His property is assessed at one million dollars  他的财产估价为100万元。
     ② decide the amount of(a tax)征收(税款):to assess a tax of ten pounds 征税10镑
    assessment [assess; -ment n.]  n.估价;评价
    assessor [assess; -or n.]  n. 估价财产的人;确定税款的人
    assessable [assess; -able a.]  adj.可估价的;可征税的

11. sedate [sed=sid坐+ate……的→坐着的,文静的]
  adj.文静的

12. consider  [con全部+sid坐+er→坐在一起→考虑到]
  v.考虑,细想;体谅,顾及;认为,把…看作

13. supersede [从上往下坐下 super(=over)+ sed(=sit)]
  vt. 代替;取代
  supersession n.取代
  Model AE-400x supersedes Model AE-200.模型AE-400X取代AE-200。

14. obsession  [妨碍地坐着ob(=in the way)+sess(=sit)]
  n.着迷;迷住
  obsess v.妄想、固有观念等)萦绕心头,不停地困扰
  obsessive  adj. 使人着迷的
  Eating is my hobby. Shopping is my obsession! 吃东西是我的兴趣,购物让我着迷!

15. sedan
  n.箱式小客车(可容纳4人以上);(17 - 18世纪的)轿子
  sedan chair 轿子

16. sedimentary
  adj.沉渣的,沉淀物的;由沉淀物生成的
  sedimentary rocks 沉积岩(如粘板岩、石灰岩等)

17. sedulous
  adj.坚忍不拔的;勤勉的,刻苦的;小心周到的
  pay him sedulous attention 密切地关注他

18. saddle
  n.马鞍; (自行车或摩托车的)车座; 鞍形架,鞍状物; (动物的)脊肉
  vt.& vi.给(马)装鞍
  vt.使承担

19. possess
  v. 持有,拥有;控制;(恶魔、邪念等)缠住,迷住(某人) *pos (=powerful,able)
  possess a large fortune 拥有大量财产
  be possessed with/by devils 着魔的
  be possessed with the idea that someone is persecuting him 着魔地认为有人在迫害他
  be possessed by envy 内心充满嫉妒
 
20. possession
   n. 所有;(pl.)所有物;财产 *pos(=powerful,able)
  illegal possession of arms 非法持有武器
  a man of great possessions 富翁

21. possessive
  adj.所有的;所有权的;[语]所有格的;占有欲强的
  possessive manner 极具占有欲的态度
  possessive adjective/case/pronoun 所有格形容词/所有格/所有格代词