1. large; big; great; huge; vast; major; important; serious; severe
大イベントが始まるんだもん。Because a big event is about to start!
2. great; prominent; eminent; distinguished
大監督は暇を持て余しているようだね。The great director seems to have time to kill.
3. -sized; as big as; the size of
4. university
東京大の研究チームが新しい薬を開発した。A research team at the University of Tokyo developed a new drug.
5. large (e.g. serving size); large option
6. long month (i.e. having 31 days)
7. feces; faeces; excrement; stool