Without going into the whole story, I first heard this word referencing a chunder bucket. I thought it was a hilarious term and we actually started calling a guy at work "Chunder Bucket" (behind his back of course). It was subsequently shortened to just chunder.
It turns out you can replace a word or two in lots of songs with chunder for comic effect. Chunderstuck is a popular one and in Bohemian Rhapsody you have chunder bolts and lightning, very, very frighting. So what is why I decided to make a t-shirt with a guy chundering lightning:
http://www.unpreparedmustard.com/uncommon/chunder-bolts
