Depending on your point of view it is either a negative or a positive term for someone non-Italian artist who is attracted to the arts and antiquities in Rome. The term was first coined to describe 16th-century Flemish painters who imported much influence from the Italian Rennaisance. These artists are also referred to as ‘italianisers’ and include the artist names of Jan Gossart, Bartholomaeus Spranger and Frans Floris de Vriendt.
Later on it has become less precisely adressed to anyone who is influenced by art in Rome who did not come from Rome originally. Great many academy painters received stipends or small grants to educate themselves in the classical world, and spent it painting sculptures, ruins and temples in Rome.