Severing the Neck and Head Detachment
Scholars have said that if someone dreams their neck was severed and their head detached, if they were sick, they would recover; if indebted, their debt would be paid; and if they had not performed Hajj, they would do so. If they were in distress or war, relief would come. If the striker was known, that good would occur through them. For a long-term sick person or someone known for righteousness, the dream might indicate their death in a good state or martyrdom.
Per Ibn Sirin's Muntakhab al-Kalam fi Tafsir al-Ahlam