1. hydrostatic lock - Noun
2. hydrostatic lock - Verb
(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.
(countable) A lock for raising and lowering boats on a canal or waterway that operates by using pressurized water to flood or drain the level inside the lock.
(countable) A locking mechanism that uses hydrostatic pressure in order to achieve a seal.
To seize up because liquid has infiltrated a mechanism for compressing gasses.
To form a seal by employing a mechanism that uses hydrostatic pressure.
Source: en.wiktionary.org