烂
The adjective 烂 (làn) means "rotten," "bad," or "terrible," and can describe both physical decay and poor quality. In colloquial usage, it is a blunt, informal way to criticize something as awful. For example, 电影评价较低,烂 means "the movie got low reviews — terrible."
这家餐厅的服务太烂了,下次不来了。
Zhè jiā cāntīng de fúwù tài làn le, xià cì bù lái le.
The service at this restaurant was terrible; I'm not coming back next time.
苹果放太久都烂了,赶紧扔掉吧。
Píngguǒ fàng tài jiǔ dōu làn le, gǎnjǐn rēng diào ba.
The apples have been sitting too long and have all gone bad; throw them away quickly.
他觉得那部电影烂得不行,完全浪费时间。
Tā juéde nà bù diànyǐng làn de bùxíng, wánquán làngfèi shíjiān.
He thought that movie was absolutely terrible, a complete waste of time.