the.com/cad

means A man who behaves dishonorably, especially toward women — breaking promises, using people, and feeling no shame about it.

from Cad started as British slang for a low-status helper — a stagecoach conductor's assistant, or an errand-runner — the kind of fellow who hung around ranks beneath a gentleman. By the 1800s, especially in university slang at places like Oxford and Cambridge, 'cad' flipped into a term students used for townsfolk, outsiders, or anyone not 'one of us' — someone common, ill-bred, no gentleman. From there it narrowed further into its modern sting: not just low-born, but low in conduct — a man whose manners might pass in a drawing room while his behavior behind closed doors would get him thrown out of one.