1. （行为或想法）疯癫的，神经的，古怪的（一些人认为用该词具冒犯意味）
If you describe someone's behaviour or ideas as loony, you mean that they seem mad, strange, or eccentric. Some people consider this use offensive.
2. 疯子，怪胎，神经病（一些人认为用该词具冒犯意味）
If you refer to someone as a loony, you mean that they behave in a way that seems mad, strange, or eccentric. Some people consider this use offensive.