The simple answer is a rake is a playboy.

More accurately, it's a historical romance novel MMC archetype who is dissolute, carefree, sexy, a charming bad boy, devoted just to pleasure, sleeps around, has no intent to ever marry—and then he meets the FMC and everything changes. He resists it at first, he swore he would be a slutty bachelor forever, but he falls in love with her and then wants to change for her, he wants to settle down with her, and he does—though still keeping his saucy rakishness, just for her—and somehow she never catches syphilis from him and they live happily ever after.

Usually rakes are rich, because how are you gonna devote your life to pleasure when you have a job? But I'm all for equal opportunity rakes. Let the tailor or shopkeeper or banker or even farmer be a seductive charming slut if he wants!