The story
From an Old English personal name *Sunna, a byname from sunna (“sun”), + dūn (“hill”).
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A civil parish in Central Bedfordshire district, Bedfordshire, England, in which the villages of Upper Sundon and Lower Sundon are located (OS grid ref TL0427). Full definition →
From an Old English personal name *Sunna, a byname from sunna (“sun”), + dūn (“hill”).
Etymology from Wiktionary, CC BY-SA 4.0.