Meaning:
“约”refers to “约定,” or “prior arrangement,” and “同” means “mutual consistency.” This idiom is a set phrase in Chinese, and the original meaning is “to do or think the same without prior consultation.” Because of the COVID-19 pandemic, however, the term has taken on a new meaning: “约” here means “约会,” or “appointment, dating,” and the phrase now means “non-dating and non-gathering have become common rules to be followed.” The new meaning has become popular among Chinese young people and is a reminder for people to keep social distancing.
Example:
A: 年底了，你们公司同事要一起聚餐么？
niándǐ le，nǐmen ɡōnɡsī tóngshì yào yìqǐ jùcān me？
Will your colleagues have a dinner together for the year end?
B: 现在疫情下还是要小心，我们都“不约而同”了。公司要发新年礼品，还是很温馨的。
xiànzài yìqíng xià háishi yào xiǎoxīn，wǒmen dōu“bù yuē ér tóng”le。 ɡōnɡsī yào fà xīnnián lǐpǐn， hái shi hěn wēnxīn de 。
Now that we should be careful under the epidemic situation, we all agree on no dating and no gathering. My company will send Chinese New Year gifts, which is very warm.