Meaning:
Literally translated as “the sixth,” this Chinese term is often used colloquially to address someone who ranks sixth in a group, by age, job title or other criteria. Gamers have given the phrase a new meaning. In such first-person shooter games as “Counter-Strike: Global Offensive,” players create five-member teams to fight off enemies. Therefore, people call those unskillful players who don’t really help teammates and don’t belong on the team “the sixth.” The term has spread to non-gamers and can be used in a more general sense to refer to those who act unpredictably and absurdly, against common sense or etiquette.
Example:
A: 我昨天买的冰淇淋放在冰箱里，怎么不见了？
Wǒ zuótiān mǎi de bīngqílín fàngzài bīngxiāng lǐ，zěnme bújiàn le？
I bought some ice cream yesterday and put it in the fridge. Why is it gone?
B: 我拿出来吃了。
Wǒ ná chūlái chī le。
I ate it.
A: 偷吃我零食！真服了你个老六了！
Tōuchī wǒ língshí！Zhēn fú le nǐ ge lǎoliù le！
You did! You ate my snack without telling me, you jackass!