[transitive verb] to take something quickly and keep or hold it:
[transitive verb] to take using sudden force:
I seized his arm and made him turn to look at me.
He seized the chance/opportunity of a free flight with both hands (= with eagerness or enthusiasm).
[transitive verb] If the police or other officials seize something, they take possession of it with legal authority:
The rebels have seized ten soldiers to use as hostages.
Political instability helped the army to seize power.
Troops yesterday seized control of the broadcasting station.
Customs officers at Heathrow have seized 60 kilos of heroin.