1. a person who robs or commits illegal violence at sea or on the shores of the sea.
2. a ship used by such persons.
3. any plunderer, predator, etc.: confidence men, slumlords, and other pirates.
4. a person who uses or reproduces the work or invention of another without authorization.
5. Also called pirate stream. Geology. a stream that diverts into its own flow the headwaters of another stream, river, etc. verb (used with object), pirated, pirating.
6. to commit piracy upon;
"tendencies can be piratical."
"policies can be piratical."
"nomads can be piratical."
"methods can be piratical."
"habits can be piratical."
This list can help you learn new vocabulary more quickly and be able explore other words more easily.