Denshi Jisho — Online Japanese dictionary

大変 たいへん 1: very; greatly;
2: () immense; enormous; great;
3: serious; grave; dreadful; terrible;
4: difficult; hard;
5: (Archaism) major incident; disaster
Common word, Adverb 
大変化 だいへんか major change; major transformation
Noun, Suru verb 
大変革 だいへんかく revolution; cataclysm; drastic change
Noun 
大変身 だいへんしん makeover; major change
Noun, Suru verb 
大変残念 たいへんざんねん deep regret; great disappointment
Noun 
大変お世話になりありがとうございました たいへんおせわになりありがとうございました thank you for all your hard work
Expression 

You can also

Look up kanji details for 大変.

Try a Yahoo Jisho search for 大変 .
Try a Goo Jisho search for 大変 .
Try a Google search for 大変 .