Tundra reached English through Russian. Merriam-Webster traces its deeper background to Kildin Sami on the Kola Peninsula. The immediate borrowing language and the earlier regional language both belong in the reveal.
tundra
A cold, largely treeless region.
Tundra came from Russian.
How tundra reached English
oldest firstKildin Sami
tūnter
‘The source of the landscape name’
into Russian
Russian
tundra / tundara
‘Tundra’
into English
English
tundra
‘The treeless landscape’