Hamster
early 17th century: from German, from Old High German hamustro ‘corn weevil’.
wiktionary
Borrowed from German Hamster, from Middle High German hamster, from Old High German hamastra, hamustro (compare Old Saxon hamustra), probably from Old East Slavic хомѣсторъ(xoměstorŭ), хомѣстаръ(xoměstarŭ), compound of (1) хомѣкъ(xoměkŭ, “hamster”) (compare Russian хомя́к(xomják), Polish chomik), from Proto-Balto-Slavic *kāmjas (compare Latvian kāmis(“hamster”), Lithuanian kãmas(“rat”), [1] and of (2) Proto-Balto-Slavic *staras (compare Lithuanian stãras(“ground squirrel”). [2] [3]
Alternatively, a borrowing into Slavic from Iranian, compare Avestan 𐬵𐬀𐬨𐬀𐬉𐬯𐬙𐬀𐬭- (hamaēstar-, “who throws down (in this case: corn stalks), oppresses”). [4] Displaced earlier term German rat.
etymonline
hamster (n.)
c. 1600, from German Hamster, from Middle High German hamastra "hamster," probably from Old Church Slavonic chomestoru "hamster" (the animal is native to southeastern Europe), which is perhaps a blend of Russian chomiak "hamster," and Lithuanian staras "ground squirrel." The older English name for it was German rat.