An Etymological Dictionary of the German Language/Beet
Beet, n., ‘bed (of a garden)’; earlier ModHG. Bett still common to UpG.; really identical with Bett, for the MidHG. has bęt, bętte, OHG. bętti, meaning also ‘(garden) bed.’ According to its form Beet (comp. Biene) has arisen from the neut. sing. badi, Bett from the cases in dj (gen. badjis, dat. badja, neut. acc. plur. badja, &c.). Comp. Goth. neut. sing. badi, neut, plur. badja. E. bed is also used in the same sense as Beet (so even in AS. riscbed), E. bed of rushes, hotbed.