泡(pào) - to steep, to soak, to brew; a bubble in Mandarin

泡 (pào) is what you do to something by leaving it in liquid. It is the verb for making tea and coffee (泡茶, 泡咖啡), for soaking laundry or dried mushrooms (泡衣服, 泡香菇), and for a hot bath or a hot spring (泡澡, 泡温泉). As a noun it means a bubble or a blister.

The colloquial extension is worth having. 泡在 plus a place means spending far too long there, in the way an English speaker might say holed up or camped out: 泡在网吧, 泡在办公室. There is a mild note of wasted time in it.

The trap is 泡 versus 煮. 泡 leaves the thing in hot water off the heat, 煮 boils it on the heat. Chinese tea is 泡, not 煮, and instant noodles are 泡面 because you pour water over them. Ask for 煮茶 and you have asked for something closer to a decoction. Note also the noun 泡沫 for foam or froth, where the tone stays fourth.