形容詞 laborious:

1. characterized by toilsome effort to the point of exhaustion; especially physical effort
   同義詞：arduous, backbreaking, grueling, gruelling, hard, heavy, operose, punishing, toilsome

1. Spent many laborious hours on the project.
   這項(xiàng)工程耗費(fèi)了長(zhǎng)期的艱辛勞動(dòng)
2. Laborious study or meditation.
   刻苦的學(xué)習(xí)勤奮的學(xué)習(xí)或思考
3. Her work is a laborious task.
   她的工作很艱苦。
4. He has a laborious style of writing.
   他的文筆不流暢。

la.bo.ri.ous

adj.（形容詞）
Marked by or requiring long, hard work:
吃力的：需要長(zhǎng)時(shí)間的艱辛勞動(dòng)的或以此為特點(diǎn)的：
例句：
spent many laborious hours on the project.
這項(xiàng)工程耗費(fèi)了長(zhǎng)期的艱辛勞動(dòng)

Hard-working; industrious.
艱辛工作的；勤勞的

來(lái)源：
Middle English
中古英語(yǔ)
from Old French laborieux
源自 古法語(yǔ) laborieux
from Latin labôriôsus
源自 拉丁語(yǔ) labôriôsus
from labor [labor]
源自 labor [勞動(dòng)]

【引伸】
labo.riously
adv.（副詞）
labo.riousness
n.（名詞）