Hello Ninon
Like Donna , not sure why you have posted on the Isle of man site.
My wife has De Meza/Demeza/Demesa/Demezer in her family tree. The name was lost when Annie Demeza married John Abraham Brown Pickard November 10, 1862 in Braddan IOM. Annie was the daughter of William Hale Demeza and Jane Tong. She was born in Manchester in 1837 , and the family moved to the Isle of Man soon after , where the last three children of her parents were born.
With others help we traced back to Isaac De Meza who was born circa 1685 and his wife Dina. He was a Papermaker in London.
We understood like Donna that the name came from Shepardic Jewish people from Portugal.
As well as England they seem to have gone to the Netherlands.

David Dwyer
Sydney, Australia