The word 牡丹亭 is formed by combining the characters 牡丹, which means "peony", and 亭, which means "pavilion"; the compound directly denotes a "Peony Pavilion", where the first part specifies the type of pavilion through modification.
Word Definition - 牡丹亭
mǔ dan tíngThe Peony Pavilion (1598), play by Tang Xianzu 湯顯祖|汤显祖[tāng xiǎn zǔ]