1）eat; take
吃早饭 eat breakfast
吃奶 take milk from its mother

2）live off
吃父母 live off one’s parents
坐山吃山 live off the mountains where your home is

干一行，吃一行
one’s profession is one’s livelihood.

1） 吃穿 food and clothing
讲究吃穿 be particular about one’s food and clothing
不愁吃穿 not have to worry about food and clothing

2) 吃喝玩乐 seek pleasure
我们难道没有比吃喝玩乐更高的人生目标吗？
Can we have no higher aim in life than mere pleasure-seeking?

3) 吃亏 suffer losses
他吃了自私的亏。
He suffered from his own selfishness.