1) not on purpose; unintentional
2) not paying proper attention
Synonyms: careless, negligent, thoughtless;
The error was both inadvertent and catastrophic.
It was an inadvertent error, to be sure, but nonetheless a mistake that required correction.
【考法1】adj. 偶然发生的： happening by chance
【例】an inadvertent encounter with a rattlesnake 偶遇响尾蛇
【近】 casual, fluky, incidental, unintentional, unplanned, unpremeditated, unwitting ,
【反】 calculated, deliberate, intended, intentional, planned, premeditated 有计划的，有预谋的
【考法2】adj. 疏忽的，不留意的： marked by unintentional lack of care
【例】The military has said it was an inadvertent error. 军方表示这是个疏忽大意的错误
【近】 careless, feckless, heedless, irreflective, thoughtless, uncaring
【反】 advertent, careful, heedful, mindful 留意的，小心的
