大変 (very, greatly)

The intensifier 大変, used adverbially to mean 'very, greatly, extremely.' Slightly more formal-leaning than とても or すごく. 大変喜ぶ ('be greatly pleased'), 大変お世話になりました ('I am greatly indebted'). As a noun/な-adjective, 大変 also means 'serious, awful' (大変なことになった 'something serious has happened').