1. spreading or transferring (cancer cells or disease) from one part of the body to another; undergoing metastasis
Usage: medical; British English spelling (American: metastasizing)
2. spreading or proliferating rapidly from one place or context to others
Usage: figurative

Examples

• The cancer cells were metastasising to the lungs and liver.
• Doctors detected the tumour before it began metastasising.
• The infection was metastasising throughout the patient's body.
• The problem of misinformation is metastasising across social media platforms.
• Without intervention, the disease continued metastasising to other organs.