noun, plural hy·drau·li [hahy-draw-lahy] /haɪˈdrɔ laɪ/, hy·drau·lus·es.
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. 2019
Examples from the Web for hydraulus
Historical Examples of hydraulus
(mosaics), where the buccinator is accompanied on the hydraulus.