Emily Dickinson Lexicon

HY-DRAUL'IC, or HY-DRAUL'IC-AL, a. [Fr. hydraulique; L. hydraulicus; Gr. υδραυλις, an instrument of music played by water; υδωρ, water, and αυλος, a pipe.]

1. Relating to the conveyance of water through pipes.
2. Transmitting water through pipes; as, a hydraulic engine. Hydraulic lime, a species of lime that hardens in water; used for cementing under water. Journ. of Science.