動詞 impair:

1. make worse or less effective
2. make imperfect
   同義詞：mar, spoil, deflower, vitiate

1. On a communications link, noise or unwanted signals that impair the receipt or correct interpretation of speech or data.
   在通信鏈路上出現(xiàn)的噪音或無用的信號，它損害語音、數(shù)據(jù)的接收或正確的解釋。
2. His illness has impaired his efficiency.
   生病降低了他的效率。

im.pair

v.tr.（及物動詞）
im.paired,im.pair.ing,im.pairs
To cause to diminish, as in strength, value, or quality:
削減，減少：造成力量、價值或質(zhì)量等的減少：
例句：
an injury that impaired my hearing; a severe storm impairing communications.See Synonyms at injure
令我聽力受損的傷；破壞了通信的大風(fēng)暴參見 injure

來源：
Middle English empairen
中古英語 empairen
from Old French empeirer
源自 古法語 empeirer
from Vulgar Latin *impôiôr3re
源自 俗拉丁語 *impôiôr3re
Latin in- [causative pref.] * see in- 2
拉丁語 in- [表示使役動詞的前輟] *參見 in-2
Late Latin pôiôr3re [to worsen] from Latin pôior pôiôr- [worse] * see ped-
后期拉丁語 pôiôr3re [使…變得更壞] 源自 拉丁語 pôior pôiôr- [更壞的] *參見 ped-

【引伸】
impair.ment
n.（名詞）