unmotivated
/ˌʌnˈməʊtɪveɪtɪd/adjective
1
- not having interest in or enthusiasm for something, especially work or study对（尤指工作, 学习）不感兴趣的, 缺少动力的。
2
- without a reason or motive没有理由的; 无动机的：
an unmotivated attack.
无缘无故的袭击。