the.com/earner

means A person or thing that brings in income — most often used for a job that reliably pays the bills.

from Simply 'earn' plus the agent suffix '-er.' 'Earn' traces back through Old English 'earnian' (to deserve, to merit through labor), part of a wider old Germanic family of words about winning or gaining something through work. The '-er' ending — the same one that turns 'bake' into 'baker' — just names whoever (or whatever) does the earning. Its modern slangy sense, as in 'a nice little earner,' picked up extra flavor from British criminal and working-class slang, where it came to mean any steady or sly source of income, legit or not.