冤

鸣冤叫屈

míng yuān jiào qū

to complain bitterly

黑籍冤魂

hēi jí yuān hún

Victims of Opium, novel by Peng Yangou 彭養鷗|彭养鸥[Peng2 Yang3 ou1], published in 1909

不是冤家不聚头

bù shì yuān jiā bù jù tóu

destiny will make enemies meet (idiom)

不白之冤

bù bái zhī yuān

unrighted wrong

伸冤

shēn yuān

to right wrongs

冤仇

yuān chóu

rancor

冤假错案

yuān jiǎ cuò àn

unjust, fake and false charges (in a legal case)

冤冤相报何时了

yuān yuān xiāng bào hé shí liǎo

if revenge breeds revenge, will there ever be an end to it? (Buddhist saying)

冤大头

yuān dà tóu

spendthrift and foolish

冤孽

yuān niè

sin (in Buddhism)

冤家

yuān jia

enemy

冤家宜解不宜结

yuān jiā yí jiě bù yí jié

It is better to squash enmity rather than keeping it alive (proverb)