词根：strain, strict, string, stress(strang) = to draw tight（拉紧）
来源于丁语的strain,strict,string,stress 意为 to bind,to tie,to draw tight。strang 是它们的变形。同义词根有来源于拉丁语的lig(li,leag,ly),cinct,nect/next 等和来自盎格鲁-撒克逊语的bond。此外，意为 to join 的
junct/join /jug也与这些词相似。
（*拉丁文stringere(=to draw tight,to compress),过去分词为strictus。（和stronge 有关系）—— 英文根字典）
同源词：
1. constrain（全部都绑上con<com(=together) + strain(=tie,draw tight)）(constrain[v.限制,约束;克制,抑制]+t→n.强迫,结束;强制力)
vt.迫使，强制，强迫；压制，抑制；束缚，拘束
constraint n.强制，强迫
constrained adj.被迫的
I feel constrained by my religious beliefs to object to capital punishment. 我的宗教信仰迫使我反对死型制度。
2. constrict（用力捆绑con<com(=together,intensive) + strict(=tie)） (constrict[v.压缩]+ion表名词→n.压缩,收缩)
vt.勒紧，压缩；（血管、肌肉）收缩；限制行动
constriction n.压缩；收缩
constrictor n.压缩机；大蟒
constricted adj.压缩的
I hate clothing that constricts my movemet. 我讨厌限制活动的衣服。
3. restrict（压着捆 re(=back,intensive) + strict(=tie,draw tight)）(re回+strict拉紧→拉回来,限制)
vt.限制，限定；约束，束缚
We had to restrict Donna's privileges because she wouldn't study enough. 我们不得不限制唐娜的一些特权，不然她不好好学习。
4. stringent（扎起来的 string (=tie)）(string拉紧+ent……的→拉紧的→紧迫的)
adj.规定严格的；严厉的，不能违背的；银根紧的，奖金短缺的
stringency n.严厉
The captain is very stringent about enforcing the curfew rules. 警察局副巡官在执行夜间宵禁令方面非常严格。
5. distrain dis分开+strain拉紧→把财产拉走)
v.（为获得租费而）扣押 *di<dis(=away)
distraint n.扣押
distrainer n.扣押人
distrainee n.财务被扣押者
distrain upon one's furniture for rent 扣押某人的家具作为房租
6. restrain (restrain抑制,制止+t→n.抑制,制止)
v.抑制；束缚 *re(=back)
restrained adj.严谨的；抑制的；克制的
7. restraint (re回+strain拉紧→拉回去→抑制)
n.抑制；束缚
without restraint 无拘无束地，自由地
the restraints of poverty 贪困的束缚
8. strain (strain拉紧→v.拉紧;紧张;扭伤;竭尽全力 n.拉紧;负担)
v.拉紧；歪曲；滥用；紧抱；（用布、筛子）过滤（液体）
n.（人的）血缘，世系；种，族；（动植物的）种，品种；气质，（性格上的）倾向；曲子，旋律，歌；诗节；口吻，语气；笔调；情调
strainet n.过滤器，筛子
strain a rope to breaking-point （如同要拉断一样）拉紧绳子
strain every nerve 竭尽全力
nervous strain 神经质
speak in a lofty strain 做慢地说话
a stain of insanity 疯狂
spaniel of good strain 优良品种的西班牙猎狗
9. strained
n.（行动）勉强的；不自然的；牵强附会的；紧张的
strained relations 紧张的（一触即发的）关系
strained cordiality 不自然的热情
strained laugh 强笑
10. unrestrained
adj.无限制的，无拘束的 *un(=not),re(=back)
11. district (dis分开+strict拉紧→分开拉,分开管理→分区;区域, 地方)
n.地域，地区；选区 *di<dis(=away)
district attorney <美>地方检察官
District council <英>区自治会
district court <美>地方法院
district leader <美>州议会议员选区的政党领导人
district office 区政府
the District of Columbia 哥伦比亚特区（即美国首都华盛顿）
single-member district system 单名选区制
multi-member district system 复数选区制
12. strict (strict拉紧→adj.[with]严格的,严厉的;严谨的,精确的)
adj.严格的，严厉的；完全的
strictly adv.严格地，严厉地
strict father 严厉的父亲
strict discipline 严格的训练
strict truth 完全属实
strict order 严令
13. stricture (strict[adj.[with]严格的,严厉的;严谨的,精确的]+ure表名词→n.谴责,严厉,束缚)
n.苛评，责难；[医]（人体异管病变性的）狭窄
14. strait
n.[和专有名词一起使用]海峡；(pl.) 危难 adj.狭窄的；苦恼的 *strait<strict(=bind)
straiten v.使窘困，使困苦
the Straits of Gibraltar 直布罗陀海峡
the Strait of Dover 多佛尔海峡
in financial straits 经济拮据的
in great straits 陷入严重困境的
strait gate 窄门
15. astringent
adj.收敛性的；严厉的，严格的 n.收敛剂 *a<ad(=to)
astringency n.收敛性；严格
16. strangle
v.扼死，使窒息 *strang<string(=bind)
17. string (string拉紧→用来拉的→绳)
n.绳（比cord细，比tread粗），线，细绳；一串东西，一连串；（乐器或弓等的）弦；（the strings）弦乐器；木偶牵线
v.给（弓、小提琴等）上弦，调弦；用线串起（珍珠等）；用绳缚，系；排成一排前进
stringency n. 严格,紧迫,说服力 (string拉紧+ency表名词→拉紧→紧迫)
a piece of string 一根线
a string of beads/pearl 一串珠子/珍珠
a string of abuses/curses 一连串的辱骂/诅咒
a string of horses 一群马
a string of cars waiting at a red light 一连串等红灯的车
have two strings to one's bow 脚踏两只船，有两手准备
pull (the )strings 在幕后操纵
string-puller 幕后操纵者
no strings (attached)/without strings （国家间的资金援助）无附带条件的/无条件的
18. stringy
adj.线状的，绳状的；多纤维的；有筋的；黏稠的；瘦而结实的
stringy meat 有筋的肉
19. constringent (constringe[v.使收缩,使收敛,压缩]+ent……的→adj.压缩的,收敛性的)
adj. 压缩的,收敛性的
20. constringe (con共同+string拉紧+e→拉到一起,收缩)
v.使收缩,使收敛,压缩
21. prestige (pre前+stige=string拉紧→在前面拉紧→声望, 威望, 威信)
n.声望, 威望, 威信
22. overstrain (over超过+strain拉紧→v.使过度紧张, 使工作过度 v.过度紧张 n.过度紧张, 过劳)
v.使过度紧张, 使工作过度
23. straight （完全张开）
adj. 直的； 连续的； 直率的； 整齐的
adv. 直地； 直接地； 坦率地； 立即
n. 直线； 直线部分
24. strangulate
v. 勒死 ;绞扼
25. stress (stress拉紧→n.&v.着重, 强调, 重读;n.压力)
n.&v. 着重, 强调, 重读
26. distress (dis分开,各种各样+stress压力→各种各样的压力→苦恼，痛苦)
v.使悲痛, 使穷困
distressful adj.痛苦的；穷困的；悲惨的
27. distress (dis分开,各种各样+stress压力→各种各样的压力→苦恼，痛苦)
n.苦恼，痛苦
28. stretch
vt. 伸展； 张开； 充分利用； 使紧张
n. 伸展； 延伸； 紧张； 弹性
vi. 伸展； 伸开
adj. 可伸缩的； 弹性的
词根词缀：cranio-, crani-, cran-
【来源及含义】Greek > Medieval Latin [c.700-c.1500]: head, skull
【同源单词】acrania, aegicrania, amphicrania, attached craniotomy, auriculocranial, bucranium
词根词缀：gnatho-, gnath-, -gnatha, -gnathan, -gnath, -gnathia, -gnathic, -gnathous
【来源及含义】Greek: jaw
【相关描述】The jaw is the name applied to the bones which contain the teeth.
The two upper jaw-bones, the maxillae, are firmly attached to the other bones of the face.
The lower jaw, the mandible, is shaped in a form similar to that of a horseshoe, and, after the first year of life, it consists of a single bone.
It forms a hinge-joint with the squamous part (thin, plate-like section) of the temporal bone, immediately in front of the ear.
Both the upper and the lower jaw-bones include deep sockets known as alveoli, which contain the roots of the teeth.
【同源单词】agnathia, anisognathous, atelognathia, brachygnathia, chaetognath, cheilognathoschisis
词根词缀：-ian
【来源及含义】Latin: suffix form of -an from -ianus, a modifier of the main word to which it is attached: belonging to, coming from, being involved in, or being like something
【相关描述】Appearing in such words as comedian, egalitarian, Bostonian, Italian, Smithsonian, mathematician, Alabamian, Californian, Arizonian, and Canadian. It is attached to the root of common or proper nouns with the meanings "of, pertaining to, from", or "like" the proper name appearing in the stem.
【同源单词】abecedarian, academician, acanthopterygian, acararian, acoustician, aeolian
词根词缀：-y
【来源及含义】Greek: a suffix that means; state of, condition of, quality of, act of
【相关描述】There hundreds of other words that use the suffix -y; however, the following entries will provide examples which will at least give you an idea of how it functions when it is attached to words.