At one time *******o, Terrantez, and Moscatel grapes were used to make
vintage Madeira. These grapes were all but wiped out by the vine
diseases and pests that struck Madeira very hard in the last half of the
1800s. However very small amounts of Vintage Madeira have been made
from these grapes since 1900. *******o Vintage Madeira is seen the least
often of the three mentioned varieties. I have Blandy *******o Vintage
Madeira 1870, Cossart Gordon *******o Vintage Madeira 1875, and Leacock
*******o Vintage Madeira 1927. M. Broadbent has tasted two of these and
rated them highly in his books.

I am not sure how the grapes got the name *******o, but this word seems
to have about the same meaning in Portugese as in English.