名詞 rash:

1. any red eruption of the skin
   同義詞：roseola, efflorescence, skin rash
2. a series of unexpected and unpleasant occurrences
   同義詞：blizzard

形容詞 rash:

1. imprudently incurring risk- George Meredith
2. marked by defiant disregard for danger or consequences
   同義詞：foolhardy, heady, reckless

1. The heat brought him out in a rash.
   因氣溫很高，他渾身長了皮疹。
2. Scratching exacerbates a skin rash.
   皮疹搔後會惡化。
3. A rash has appeared on his body.
   他身上出現(xiàn)了丘疹。
4. His rash outburst incurred the displeasure of the judge.
   他勃然大怒使法官不悅。
5. While you have this rash you are still infectious.
   身上還有這種疹子，就仍然有傳染性。
6. He made a rash decision now he's suffering for it.
   他做決定太倉促--現(xiàn)在可吃到苦頭了。
7. Hot weather makes her come out in a rash.
   因天氣炎熱，她起了皮疹。
8. Don't do anything rash.
   不要魯莽行事。

rash

adj.（形容詞）
rash.er,rash.est
Characterized by or resulting from ill-considered haste or boldness.See Synonyms at reckless
魯莽的：以輕率的快速和莽撞為特點的或由此而發(fā)生的參見 reckless
Archaic Quick in producing a strong or marked effect.
【古語】 快速的：一下子就產(chǎn)生強烈或明顯效果的

來源：
Middle English rasche [active]
中古英語 rasche [活躍的]
perhaps from Old English -raesc in logrôsc [lightning]
可能源自 古英語 -raesc 在 logrôsc之中 [閃電]
or from Middle Dutch
或源自 中古荷蘭語
or Middle Low German rasch
或 中古低地德語 rasch

【引伸】
rash.ly
adv.（副詞）
rash.ness
n.（名詞）

---------------另--------------
rash
rash 2

n.（名詞）
A skin eruption.
疹：皮膚上的突起
An outbreak of many instances within a brief period:
爆發(fā)：短時間內(nèi)一連串事件的爆發(fā)：
例句：
a rash of burglaries.
一連串的打家劫舍案

來源：
Possibly from obsolete French rache [a sore]
可能源自 已廢法語 rache [疼痛]
from Old French rasche [scurf]
源自 古法語 rasche [皮屑，頭垢]
from raschier [to scrape, scratch]
源自 raschier [擦，抓，搔]
from Vulgar Latin *r3sic3re
源自 俗拉丁語 *r3sic3re
from Latin r3sus [past participle of] r3dere * see rôd-
源自 拉丁語 r3sus [] r3dere的過去分詞 *參見 rôd-