吃醋[chī cù]
Literal：to eat vinegar.
Figuratively meaning： to be jealous (of a rival in love).
e.g.
tīnɡ qǐ lái nǐ chī cù le 。
听起来你吃醋了。
It sounds like you are jealous.
dānɡ tā fā xiàn tā ài bié rén de shí hou ，
当他发现她爱别人的时候，
tā chī cù le 。
他吃醋了。
He was jealous when he discovered that she loved someone else.