搭子pal

搭子 is a Shanghainese term originally used to refer to card-playing companions. Its usage has since broadened to denote companions for any activity. You might spot Chinese folks posting about seeking 饭搭子 (fàn dā zi, meal companions), 旅游搭子 (lǚ yóu dā zi, travel buddies), 减肥搭子 ( jiǎn féi dā zi, weight-loss partners), or even 上厕所搭子 (shàng cè suǒ dā zi, bathroom companions).

Source：the Beijinger