decline

refuse, decline, reject, repel, deny

名词 decline:

1. change toward something smaller or lower
   同义词：diminution
2. a condition inferior to an earlier condition; a gradual falling off from a better state
   同义词：declination
3. a gradual decrease; as of stored charge or current
   同义词：decay
4. a downward slope or bend
   同义词：descent, declivity, fall, declination, declension, downslope

动词 decline:

1. grow worse
   同义词：worsen
2. refuse to accept
   同义词：refuse, reject, pass up, turn down
3. show unwillingness towards
   同义词：refuse
4. grow smaller
   同义词：go down, wane
5. go down
6. go down in value
   同义词：slump, correct
7. inflect for number, gender, case, etc., "in many languages, speakers decline nouns, pronouns, and adjectives"

1. She is on the decline, and may die soon.
   她的健康每况愈下，可能不久于人世。
2. The wall declined slightly on account of the earthquake.
   墙壁因地震而倾斜。
3. He spent his declining years in the country.
   他在乡间度过晚年。
4. I wish prices would decline.
   但愿物价下降。

de.cline

v.（动词）
de.clined,de.clin.ing,de.clines
v.intr.（不及物动词）
To express polite refusal.
婉拒，谢绝

To slope downward; descend.
向下倾斜；下倾
To bend downward; droop.
向下弯曲；下垂
To degrade or lower oneself; condescend.
降低自己的身份；屈尊俯就
To deteriorate gradually; fail.
逐渐恶化；衰败

To sink, as the setting sun.
下沉，如落日
To draw to a gradual close; wane.
接近结束；消逝
v.tr.（及物动词）
To refuse politely:
婉辞，谢绝：
例句：
I declined their offer of help.See Synonyms at refuse
我谢绝了他们提出的帮助参见 refuse

To cause to slope or bend downward.
使…倾斜或使…向下弯曲
Grammar To inflect (a noun, a pronoun, or an adjective) for number and case.
【语法】 字尾变化：使（名词，代词或形容词）的数和格发生变化
n.（名词）
The process or result of declining, especially a gradual deterioration.
衰退：衰落，尤指逐渐恶化的过程或结果
A downward movement.
下降，落下：向下的运动
The period when something approaches an end.
后期：接近结束的时期
A downward slope; a declivity.
斜坡：下坡；下倾的斜坡
A disease that gradually weakens or wastes the body.
消耗病：使身体逐渐衰弱或消瘦的疾病

来源：
Middle English declinen
中古英语 declinen
from Old French decliner
源自 古法语 decliner
from Latin dôclon3re [to turn away, bend downward, change the form of a word]
源自 拉丁语 dôclon3re [转过脸，向下弯曲，改变词形]
dô- [de-]
dô- [向下]
-clon3re [to lean, bend] * see klei-
-clon3re [倾斜，弯曲] *参见 klei-

【引伸】
declin.able
adj.（形容词）
declin.er
n.（名词）