profit

The root profit hides a surprisingly active picture inside a word we now think of as purely financial. It comes from Latin profectus, the past participle of proficere, "to make progress, to advance, to be useful." Break proficere down and you see two familiar pieces: pro- (forward) + facere (to do, to make). So at its core, to profit is literally "to make forward" — to move ahead, to gain ground. Originally this had nothing specifically to do with money. To profit from something meant to advance because of it, to be the better for it: you profit from good advice, you profit from experience. That broad sense survives in phrases like "What does it profit you?" and "profit from your mistakes." Over time, in the world of trade and accounting, the most measurable kind of "advance" became financial, and profit narrowed to mean the money left over after costs — the amount by which you've moved forward. From this base, English builds a tight, transparent family. Add -able and you get profitable: capable of producing gain, whether the gain is money (a profitable business) or benefit (a profitable discussion). Add the agent ending -eer and you get profiteer, but with a sour twist: a profiteer is someone who makes excessive or unfair profit, especially from others' hardship — a war profiteer. Add -less and you get profitless: producing no gain at all, effort that goes nowhere. So the whole family pivots on a single idea — moving forward, gaining ground — that started broad (any kind of advancement), narrowed to money in everyday use, but still flashes its older, wider meaning whenever you say someone profited from an experience. Keep the pro- + facere image in mind and even the financial sense stays vivid: a profit is the distance you've moved forward.