According to The Place Names Of Wiltshire (English Place-Name Society Volume XVI) by J.E.B. Gover, Allen Mawer and F.M. Stenton, published by Cambridge University Press, 1970:
Stockton. Roakham Bottom (Rokecombe c.1570 Documents in the possession of the Earl of Pembroke at Wilton House, Rochum Bottom 1808 Ordnance Survey) (6″) was the home of William de Roucombe (1341 Nonarum Inquisitiones, 1807). It is probably referred to in the bounds of Stockton in 901 (Birch, Cartularium Saxonicum, 3 vols., 1885-93) in the phrase ofer radune sweoram ofer nacum (sic). Probably ‘roe valley,’ v. cumb.