billingsgate
Profane, abusive language; coarse words.
You wouldn't have believed the billingsgate which poured forth from that boy's mouth.
Where it comes from
From the London, England fishmarket Billingsgate: "Billingsgate is the market where the fishwomen assemble to purchase fish; and where, in their dealings and disputes they are somewhat apt to leave decency and good manners a little on the left hand." (Dictionary of the Vulgar Tongue, 1811).
Adapted from the Wiktionary entry billingsgate (CC BY-SA 4.0).