also: ジャーヨウ · ジャヨウ
interjection
keep going; hang in there; go for it
Chinese-derived interjection used to cheer someone on, similar to 頑張れ. The literal gloss 'add oil' is a direct translation of the Chinese characters but is not used as an English expression.
from Chinese jiāyóu
加油！あと少しだよ。
Keep going! Just a little more.
試験がんばってね。加油！
Good luck on your exam. You can do it!
加油 is a Chinese loanword used as a casual cheer, while 頑張れ is the native Japanese equivalent and more standard across all situations.
Borrowed from Chinese 加油 (jiāyóu), literally 'add oil', used as an expression of encouragement.