experiment [ɪk'spɛrəmənt]
n实验;试验
vi进行实验,试验

peril ['peril]
n1: exposure to the risk of being injured, destroyed, or lost : danger
2: something that imperils or endangers : risk
v to expose to danger
n. 危险；冒险
vt. 危及；置…于险境

短语
1.at someone' s peril 由某人自担风险；自负后果
2.at the peril of 冒…的危险
3.in peril of 冒着…的危险；使发生危险；有…的危险；在危险中；在危急中
4.in the time (或hour) of peril 在危险的时刻
5.Keep off at your peril! 走开点，否则危险自负!

例句
He periled his life to save the drowning boy.
他冒险去救那个溺水的儿童。
All, equally, are in peril, and, if the peril is understood, there is hope that they may collectively avert it.
大家都是面对同样的危险,如果大家明白这种危险,就有希望通过集体努力避免它的发生。

imperil [im'peril]
to put something or someone at risk or in danger of being harmed or destroyed
vt. 危及；使陷于危险

例句
Water pollution imperils all kinds of marine life.
水质污染危及所有海洋生物。
The whole project is imperilled by lack of funds.
整个工程因缺少资金而陷于危险之中。

perilous ['periləs]
extremely dangerous
adj. 危险的，冒险的

例句
The journey through the jungle was perilous.
穿过丛林的旅行充满了危险。
Learning without thought means labor lost; thought without learning is perilous.
学而不思则罔,思而不学则殆.

error ['erə]
a mistake
n. 误差；错误；过失
[古语]游荡，漫游

errant ['erənt]
knight errant ：a knight who travelled around, looking for adventure
doing something that is wrong; not behaving in an acceptable way
adj. 错误的；偏离正路的；不定的；周游的；

aberrant[æ'berənt] ab-away
straying from the right or normal way
different from what is typical or usual, especially in an unacceptable way
not usual or not socially acceptable
adj. 异常的；畸变的；脱离常轨的；迷乱的