氓

lost (亡) + people (民) = drifting folk, riffraff

民 points to common people who have drifted from their home or proper station — wanderers and vagrants. 亡 gives the sound máng and also quietly echoes the idea of loss or flight.

街上有几个流氓在闲逛。

他小时候跟流氓混在一起，后来改好了。