Definition of "filthily"

[…] I waded through with some difficulty, and one of the footmen wiped me as clean as he could with his handkerchief, for I was filthily bemired; and my nurse confined me to my box, till we returned home […]

1726 October 28, [Jonathan Swift], Travels into Several Remote Nations of the World. […] [Gulliver’s Travels], volume I, London: […] Benj[amin] Motte, […], part II (A Voyage to Brobdingnag)

I felt a peculiar shrinking from those pallid bodies. They were just the half-bleached colour of the worms and things one sees preserved in spirit in a zoological museum. And they were filthily cold to the touch.

1895 May 7, H[erbert] G[eorge] Wells, “Chapter 6”, in The Time Machine: An Invention, New York, N.Y.: Henry Holt and Company

Could it be that he, Stephen Dedalus, had done those things? His conscience sighed in answer. Yes, he had done them, secretly, filthily, time after time, and, hardened in sinful impenitence, he had dared to wear the mask of holiness before the tabernacle itself while his soul within was a living mass of corruption.

1916, James Joyce, chapter 3, in A Portrait of the Artist as a Young Man‎