detract

动词 detract:

1. take away a part from; diminish
   同义词：take away

1. A little crack detracts from the value of the vase.
   小小的裂痕减损那个花瓶的价值。
2. His high voice and unpleasant appearance detract from his effectiveness as a speaker.
   说话语调高，加之外貌不太好看，有损于他作为演讲者的影响。

de.tract

v.（动词）
de.tract.ed,de.tract.ing,de.tracts
v.tr.（及物动词）
To draw or take away; divert:
取走；分心，转移：
例句：
They could detract little from so solid an argument.
他们从这如此坚实的论证中几乎挑不出一点儿毛病

Archaic To speak ill of; belittle.
【古语】 诽谤；毁损
v.intr.（不及物动词）
To undergo reduction in value, importance, or quality; become reduced, as in effect. Often used withfrom :
贬低，减损：降低价值，重要性或质量；降低效果。经常与from 连用：
例句：
testimony that only detracts from the strength of the plaintiff`s case.
仅仅降低了原告案情有力的证词

To divert or draw away qualities or a quality essential to the value, importance, or effect of something:
减损：分离或损害了决定某事价值，重要性或效果的特性：
例句：
a decorating scheme that detracts but does not enhance.
一个不但没增色反而减色的装修方案

来源：
Middle English detracten
中古英语 detracten
from Latin dôtrahere dôtr3ct- [to remove]
源自 拉丁语 dôtrahere dôtr3ct- [移走]
dô- [de-]
dô- [前缀，表.降低.]
trahere [to pull]
trahere [拉曳]
Sense 2, from Latin dôtr3ct3re [frequentative of] dôtrahere [to take away]
释义2，源自 拉丁语 dôtr3ct3re [] dôtrahere的重复动词 [取走]

【引伸】
detrac.tor
n.（名词）