Green’s Dictionary of Slang

1. one who suffers regularly and often from venereal disease.

1890–1904

Farmer & Henley Sl. and Its Analogues.

2. a promiscuous man.

1890–1904

Farmer & Henley Sl. and Its Analogues.

3. a specialist in venereal diseases.

1926

‘Cristofero Columbo’ in Canfield Coll. Now in the town of Madrid, the clapsters were not many, / And the very best clapster in the town was a God-damned Jew named Benny.