[hy.drau.lic] adj [L hydraulicus, fr. Gk hydraulikos, fr. hydraulis hydraulic organ, fr. hydr- + aulos reed instrument--more at alveolus] (1661) 1: operated, moved, or effected by means of water
2. a: of or relating to hydraulics "~ engineer" b: of or relating to water or other liquid in motion "~ erosion"
3: operated by the resistance offered or the pressure transmitted when a quantity of liquid (as water or oil) is forced through a comparatively small orifice or through a tube "~ brakes"
4: hardening or setting under water "~ cement" -- hy.drau.li.cal.ly adv