These categories are not well defined.

这些类别划分得不太明确。

《牛津词典》

If the project is not well defined, with a clear vision for the final result from inception, there's a high risk of failure.

如果项目没有经过良好定义，并且在项目启动时没有关于最终结果的远景，则失败的可能性就非常大。

youdao

One of them is the use of Asian characters in the text. Korean characters are not well defined and font sizes tend to be small.

其中一个问题就是，教材中用到亚洲文字是，例如，韩语文字显示不是很好，字体偏小。

youdao

Studying how the parasite interacts with its insect host is difficult, he said, because the mosquito's biochemical and genetic make-up are not well defined.

BBC: Infected flies boost malaria hope

In a business like military electronics where the boundaries between product categories are not well defined and requirements change quickly, mass and diversity are crucial to survival.

FORBES: Wave Of Consolidation May Be Coming In Military Electronics

The list of higher emotions is not as well defined as that of the baser ones, but they include things such as guilt, embarrassment, shame and sympathy.

ECONOMIST: Emotion is essential to human survival