to do your best, to try your hardest

一生懸命(いっしょうけんめい)	Bust ass at xxx! adjective. 一生懸命頑張ってる (she’s really doing her best!). $$$

努力(どりょく)	Like 一生懸命 but a noun. one’s efforts.

必死(ひっし)	Desperate, life-or-death, last-minute efforts.

奮闘(ふんとう)	Stronger than 一生懸命 or 努力. Best defined as “epic struggle.” People struggle for justice in South Africa or for women’s right to vote. A struggle to keep one’s business going when a Wal-Mart moves in across the street.