My name is José Varela; I am Portuguese, and live in Algarve the most southern region of Portugal.
al-Farrob is only a nickname I have been using on the Internet for some years. As far as I know it has no meaning at all. And its arab look is only that, an appearance
"Alfarroba" means carob (ceratonia siliqua), which is very common in Algarve, and inexistent in the rest of the country; and the Arabs have been here for more than 5 centuries, thus leaving great influence, greater than in the rest of the country.
So this nickname is only a pun mostly to be understood by the Portuguese themselves:)
It is more widely known than my real name so I continue using it.