Earn a/your crust
Definition 1 of 1
Pro Tip 1/3Everyday Use
The phrase is commonly used in casual conversations, not in formal contexts. 
After college, I moved to the city to earn my crust.
Pro Tip 2/3Metaphorical Meaning
Earning a crust metaphorically means earning enough to buy basic food, like bread, hence the reference to 'crust'. 
I'm not rich, but I earn a crust.
Pro Tip 3/3Struggle Implied
The phrase often suggests a struggle or just getting by, rather than abundance or comfort. 
These days, it's tough to earn a crust.