1(bound form) (poetry) antithetical couplet
2(bound form) to ally oneself with; to unite; to combine; to join
Example
xiàn zài现在wǒ men我们chà bu duō差不多yǒu有tóng yàng同样de的shuǐ píng水平liǎo了，wǒ men我们kě yǐ可以kāi shǐ开始xué xí学习jǐ几duàn段sì四shǒu手lián联tán弹。
现在我们差不多有同样的水平了，我们可以开始学习几段四手联弹。
Now that we are at nearly the same level, we can start learning some piano duets.