Numidia /n(j)uˈmɪdiə/ noun2 •(historical) A historical region and ancient Berber kingdom located in North Africa, initially situated in modern Algeria but later expanding into Tunisia and Libya.Massinissa made many inward parts of Barbarie and Numidia in Africk (before his time incult and horrid) fruitful and battable by this means. — 1621 •(historical) A former province of the Roman Empire, approximately located in modern northeastern Algeria.