A slang term for money; common alternative spellings are spondulicks, spondoolicks, and spondulix. I have also heard "spon(d)s". Originally US college slang, dating from the 1850s, it is a learned joke: it appears to be from the from the Greek spondulikos, the adjective of spondulos.
The British slang expert Eric Partridge said this was a kind of seashell used as money. However, it has been questioned whether the spondulos ever was used as currency, and an alternative explanation is that the word meant drum or tambour and thus also vertebra, and that the slang use came from the stacked appearance of coins. (This explanation is attested from 1867.) The OED calls it a fanciful coinage, and the modern NODE even marks it as British slang. It is now well known in Britain and Australia.
In Chapter 13 of Huckleberry Finn the boat-owner says, "for, says I, a sailor's life's the life for me, and I'm derned if I'd live two mile out o' town, where there ain't nothing ever goin' on, not for all his spondulicks and as much more on top of it."
It featured in one of W.C. Fields's classic exchanges: in My Little Chickadee he (as Cuthbert J. Twillie) says to a mark (Cousin Zeb), "Have you any of the elusive spondulicks on you?". Satisfied, he sets up a poker game. The mark innocently asks, "Is this a game of chance?", and Fields reassures him, "Not the way I play it, no."
Discussed by Michael Quinion at www.quinion.com/words/weirdwords/ww-spo1.htm