But I was so puzzled that when I tried to sing, I couldn't remember a word of the verse I had written.

verse 是名词，指诗歌中的"节"或"段落"，通常由几行诗句组成，在歌曲中对应歌词的一个段落。这个词来自拉丁语 versus，原意是"犁沟、一行文字"，引申为诗歌的分节单位。