Zi Collection, Page Position: Lower. Radical: Knife (dao). Wen. Kangxi Dictionary Stroke Count: 6 strokes. Page 137, Entry 3.
Tang Rhymes (Tangyun), Collected Rhymes (Jiyun), Rhyme Assembly (Yunhui), and Correct Rhymes (Zhengyun) all state the fanqie pronunciation is notated as wu plus fen, and it is pronounced the same as wen.
Explaining Graphs and Analyzing Characters (Shuowen Jiezi) defines the term as to cut the throat.
Jade Chapters (Yupian) defines it as to cut.
Record of Rites (Liji) records in the Tangong chapter: For those who do not reach a certain standard, cut their throats.
Records of the Grand Historian (Shiji) records in the Biographies of Zhang Er and Chen Yu: The two individuals formed a bond, becoming life-and-death companions ready to cut their throats for one another.
Rhyme Assembly (Yunhui) records: Sometimes also written in a variant form pronounced mo.