The word 桐梓 is formed from two characters, each constructed as a phono-semantic compound. 桐 combines the semantic component 木 (tree) with the phonetic component 同 (tóng) to denote the paulownia tree. 梓 combines the semantic component 木 (tree) with the phonetic component 宰 (zǎi) to denote the catalpa tree. Together, they form a compound word used as a place name derived from these tree types.