混 has a colloquial 'surviving/getting by' meaning: 混日子 (muddle through the days), 混得不错 (doing pretty well for yourself). It implies a casual, not very ambitious approach to life.
grammar
混 is usually hùn (4th tone). In the rare word 混蛋 (húndàn, bastard), some pronounce it hún (2nd tone), though hùndàn is also accepted.
