- a pipe organ of ancient Greece and Rome using water pressure to maintain the air supply.
Origin of hydraulus
1870–75; < Latin < Greek hýdraulos water organ, equivalent to hydr- hydr-1 + aulós pipe
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for hydraulus
(mosaics), where the buccinator is accompanied on the hydraulus.