Green’s Dictionary of Slang

swaddler n.1

also swadler
[Charles Wesley, Journal, 10 September 1747: ‘We dined with a gentleman, who explained our name to us. It seems we are beholden to Mr Cennick for it, who abounds in such like expressions as, “I curse and blaspheme all the gods in heaven, but the babe that lay in the manger, the babe that lay in Mary’s lap, the babe that lay in swaddling clouts”, &c. Hence they nicknamed him, “Swaddler, or Swaddling John”; and the word sticks to us all, not excepting the Clergy.’ Hotten (1860) adds that during the sermon, ‘an ignorant Romanist, to whom the words of the English Bible were a novelty [...] shouted out in derision “A swaddler! a swaddler!”, as if the whole story were the preacher’s invention’]

1. [mid-18C–19C] a Methodist.

2. [mid–late 19C] any type of Protestant.