noun: Abbreviation of hydrostatic lock. (a condition affecting a compression device that compresses gases, having been infiltrated by an unsustainable amount of incompressible liquid, or, being unable to further compress gases, locking the device in place) [(mechanical engineering, usually uncountable) A condition that arises when a device which compresses gases seizes up because of the infiltration of liquid, which prevents further compression.]
verb: Abbreviation of hydrostatic lock. (to enter a hydrolock) [To seize up because liquid has infiltrated a mechanism for compressing gasses.]