Police stopped him for driving erratically.是什么意思？

Police stopped him for driving erratically.

警察因其驾驶不循规则而把他拦下了。

police

n. 警察部门，警方，警察，治安；vt. （警察、军队等）巡查，维护治安，（委员会等）监督，管制；adj. 警察的，有关警察的；

例句
A police investigation yesterday absolved the police of all blame in the incident.
警方昨天的调查廓清了其在此事件中的任何责任。

stopped

v. 停止( stop的过去式和过去分词 )，中断，逗留，（使）停止工作；

例句
He stopped to try to adjust his vision to the faint starlight...
他停下脚步试着让眼睛适应微弱的星光。

him

pron. (he的宾格)他；

例句
They said goodbye to him as he got aboard the train at Union Station.
当他在联合火车站登上火车之际，他们向他道别。

for

prep. 为，为了，倾向于，关于，当作；conj. 因为，由于；

例句
I've come looking for a bit of advice.
我特来讨教。

driving

n. 操纵，驾驶；adj. 推进的，强劲的，雨、雪等猛烈的，倾泻而下的；v. 强迫( drive的现在分词)，驱使，驱赶，消除；

例句
Better driving equipment will improve track adhesion in slippery conditions.
较好的驾驶设备能够提升在湿滑路面上的抓地力。

erratically

adv. 不规律地，不定地；

例句
The aircraft bumped along erratically without gathering anything like sufficient speed.
飞机忽上忽下，飞行很不平稳，根本未达到应有的速度。