Green’s Dictionary of Slang

an unpleasant person.

1959		C. MacInnes Absolute Beginners 10: It’s the kids themselves [who are responsible] for buying the EPs these elderly sordids bribe the teenage nightingales to wax.
2024		J. Meades Empty Wigs (t/s) 113: You’d never take them [i.e. a dogger n.2 ] for crotch sordids if you pass them in the street.