Having an open top. / (of a vehicle) Having no roof, or having a top folded or detached.

(UK) A double-deck bus with an open, or partially open, top deck.

The control mechanism by which a door is latched and unlatched. / Any of various devices to automatically open a door in response to a sensor or signal sent from a controller.

(military) A military unit formed up so as to allow space between its ranks. / (nautical) A naval formation in which ships are four cables'-length (2880 feet) apart.

(mechanics) A type of differential gear used in automobile construction, allowing for output shafts to have different angular velocity, while equalizing torque applied to each output shaft.

(Australia) Freedom to act without repercussions; free rein.

(law) A requisite condition of adverse possession stipulating that the disseisor's occupation of the property must be visible and provide reasonable (if tacit) notice to the disseisee.

(philosophy) A philosophical concept that refers to the universal possibility of imprecision in empirical statements.

simple past tense and past participle of open the range

(military) To draw oneself or one's vehicles (warships, tanks, aircraft, etc.) out of range of the enemy's fire.