Wiktionary
thruppence
n. (context British informal dated English) threepence (''in pre- or post-decimalisation currency'')
Usage examples of "thruppence".
Prince Edward Theatre, a pitch he has known since it was the old London Casino, remembers eating three courses for one and thruppence in those sepia days, when the riot of bleached shop blinds gave the corner of Old Compton Street and Dean Street the look of a three-masted schooner in full sail.
Amy was pleased to see, however, that there was none of the tense atmosphere she would expect from high gaming, and the coins in use were mainly pennies, thruppences, and sixpences.