Meaning - Someone doesn't care whatever the
other people's pressure or threats on him/her. It's similar to "Not
give a damn"
or "Not give a shit" in English.
For example:
你别吓我，我不吃这一套。(Don’t threaten on me, I don't give a damn.)
他不吃这一套，我们要换个方法对付他。(This strategy doesn’t work on him, we need to find another way to deal
with him.)
韭菜 - chive, a perennial plant related to the onion and having slender leaves used as a vegetable in China. Chives grow quickly and can be harvested many times during the growing season.
Recently, 韭菜 has a derived meaning - the lowest class people. 割韭菜 (harvesting the chives), meaning - the government make the people suffer by the unfair policies.
甜酸苦辣—— The original meaning: sweet, sour, bitter, spicy. The derive meaning - various experiences from life.
e.g. 他活到这个岁数，人生的甜酸苦辣都尝遍了。
At his age, he has experienced everything in life, including happiness or disaster.
柴米油盐酱醋茶——The original meaning: firewood, rice, cooking oil, salt, soy sauce, vinegar, tea. The derive meaning: Trivial essential things in life.
e.g. 生活就是柴米油盐酱醋茶。
Life is all about the trivial essential things.
辣——The original meaning: spicy. When 辣 is compounded with 妹 or 妈，it means outgoing. e.g. 辣妹，outgoing girl. 辣妈，outgoing mom.
泼辣——outgoing, bold, not shy.
e.g. 这个女子很泼辣。
This woman is fearless.
甜滋滋——The original meaning: sweet. The derive meaning: happy.
e.g. 这位妈妈在母亲节收到孩子的礼物，心里甜滋滋的。
This mom got mother's day gifts from her kids, feeling very happy.
甜蜜蜜——The original meaning: sweet. The derive meaning: happy.
e.g. 大家祝福这对新人生活永远甜蜜蜜。
Everyone wishes this newly-wed a happy life forever.
苦哈哈——The original meaning: bitter. The derive meaning: bitter, difficult.
e.g. 因为疫情，很多餐馆都少了很多客人，苦哈哈地撑着。
Many restaurants have lost lots of costumers because of the pandemic, they're struggling to keep on.
酸溜溜——The original meaning: sour. The derive meaning: combination of jealous and dejected.
e.g. 他的同事升职了，他心里酸溜溜的不是滋味。
His coworker got promotion, he feels dejected.
吃醋——The original meaning: to sip vinegar. The derive meaning: envy of someone because of affection
e.g. 那人因为女友和别的男人打情骂俏而大为吃醋。
That man was jealous because his girlfriend flirted with other men.
醋意——The original meaning: vinegar, The derive meaning: jealousy.
她看到男友向别的女孩献殷勤，醋意大发。
She couldn't hide her jealousy when she saw her man ingratiated other girl.
刀子嘴，豆腐心——The Original meaning: knife mouth, tofu heart. The derive meaning: tough word but soft heart.
e.g. 他这个人刀子嘴，豆腐心，没有恶意。
This guy is tough in mouth but soft in heart, hasn't any hostility.
只only见see 贼thief吃eat肉meat，没didn't见see贼thief挨打was beaten,
The literal meaning - only see the thief eat the meat, didn't see the thief being beaten.
The actual meaning - Don't envy those money obtained by improper means.
e.g. 别羡慕那家伙外表风光，你是只见贼吃肉，没见贼挨打，他其实好赌成性，一身烂债。
Don’t envy that guy’s appearance. You only saw the thief eat meat and didn’t see the thief being beaten. He's actually a gambler and a bad debt.
The literal meaning- I‘ve never eaten pork, haven't I seen pigs run?
The actual meaning - Although I haven't experienced that situation, I knew it from other ways.
e.g. 张三老爱吹嘘自己的房子多气派，其实，他的房子算什么呀。我没吃过猪肉，还没见过猪跑啊？我当房产经纪时，见过的豪宅多了去了。
Zhang San always loves to brag about how luxurious his house is. In fact, his house is nothing. Although I‘ve never eaten pork, haven't I seen a pig run? When I was a real estate agent, I had seen lots of luxury houses.