1
to take possession of (forcibly);to take over (a company, account, etc.);to capture (a castle, enemy position, etc.);to seize;to occupy;to usurp
軍が政府を乗っ取った。
The army took over the government.
2
to hijack (a plane, ship, etc.)
乗っ取り犯人の要求には応じられない。
We cannot meet the demands of the hijackers.
Other forms
乗っとる 【のっとる】 (search-only kanji form)