hi! if you're just looking for etymology, you could try any good, large dictionary or a specialist etymology dictionary. A handy free reference is the Online Etymology Dictionary here:

Hungary

c. 1300, from Medieval Latin Hungaria (also source of French Hongrie), probably literally meaning "land of the Huns," who ruled a vast territory from there under Attila in 5c. The people's name for themselves we transliterate as Magyar. Middle English uses the same words for both Attila's people and the Magyars, who appeared in Europe in 9c. From the same source as Medieval Greek Oungroi, German Ungarn, Russian Vengriya, Ukrainian Ugorshchina. The Turkish name for the country, Macaristan, reflects the indigenous name. Related: Hungarian.

Also, here are a few earlier posts that discuss the name

• Why is Hungary called Hungary when Hungary is made up of Magyars?

• Does the English name for the Hungarian people come from contemporary Europeans erroneously thinking that the invading Magyar were the return of the Huns?

• Who were the Huns? And where did they come from/ where did they go? - scroll about half-way down

• What is the relationship between Huns and Hungarians (Magyars)?

if you have followup questions on locked posts, ask them here & include the relevant user's username so they'll be auto-paged