To grasp suddenly and forcibly; take or grab: seize a sword. To grasp with the mind; apprehend: seize an idea and develop it to the fullest extent. To possess oneself of (something): seize an opportunity. To have a sudden overwhelming effect on: a heinous crime that seized the minds and emotions of the populace. To overwhelm physically: a person who was seized with a terminal disease. To take into custody; capture. To take quick and forcible possession of; confiscate: seize a cache of illegal drugs. To put (one) into possession of something. To vest ownership of a feudal property in. Nautical To bind (a rope) to another, or to a spar, with turns of small line. To lay sudden or forcible hold of. To cohere or fuse with another part as a result of high pressure or temperature and restrict or prevent further motion or flow. To come to a halt: The talks seized up and were rescheduled. To exhibit symptoms of seizure activity, usually with convulsions.