Definition of "Jos"

[…] Mr. Jos had the honour of leading out the Countess of Schlusselback, an old lady with a hump back, but with sixteen good quarters of nobility and related to half the royal houses of Germany.

1847 January – 1848 July, William Makepeace Thackeray, chapter 63, in Vanity Fair […], London: Bradbury and Evans […], published 1848

Joseph Rudge and his family had for some time been living in the new hut, about twenty miles from the head station. […] "Right, Jos," said Mat Clark, his mate; […]

1867, William Henry G. Kingston, editor, Taking tales for cottage homes, pages 9–10