啉

used in the transliteration of the names of organic compounds such as porphyrin 卟啉[bu3 lin2] and quinoline 喹啉[kui2 lin2]

mouth / classifier for things with mouths (people, domestic animals, cannons, wells etc) / classifier for bites or mouthfuls

woods / forest / CL:片[pian4] / circle(s) (i.e. specific group of people) / a collection (of similar things)