I'm finding this handwriting hard to read here. I'm quite certain it ends in "-tysis" but the first few letters are difficult to decode.
Does anyone know what the cause of death may be here? This is from Forfar, Scotland in 1857.
Paralysis.
Determining the underlying cause is pure speculation, but suffice it to say that the person had some sort of neurologic disorder. Causes could range from trauma to infectious or inflammatory disease, and everything in between.
A useful source to identify causes of death on old death certificates is Antiquus Morbus. For paralysis, it states:
Palsy. A disease characterized by loss or great diminution of the power of voluntary motion, affecting any part of the body. [Thomas1875].
Abolition of function, whether complete or partial; esp., the loss of the power of voluntary motion, with or without that of sensation, in any part of the body; palsy. [Webster1913].
Loss or impairment of the ability to move a body part, usually as a result of damage to its nerve supply. [Heritage]
"paralysis" was first used: 1525. [Webster]