Rhabdomancy is the use of a rod (rhabdo-) for the purpose of divination (-mancy), specifically the technique of using a dowsing rod to find underground sources of water or minerals.
Needless to say, rhabdomancy is about as effective as haruspicy, the least vegan of all the ancient divination practices.
I stumbled across rhabdomancy by complete chance while browsing the splendid interactive lexicon, Visuwords.
By complete chance, really? Or was I guided by a higher power?