Survey of English Place-Names

Historical Forms

• the Hoga of Cossdoune 1240 Dartmoor 15th

• Costendoune 1240 Buckfast

• Cosdon al. Cosson 1608 Dartmoor

• Cawson-hill 1797 Polwhele

Etymology

There is not much to go upon here. We have perhaps as the first element a pers. name Cost (a ) found also in Costessy (Nf), DBCosteseia , Cosford (Sa), Costesford BCS 22, and in a diminutive form in Costices myln (BCS 1076). Cf. OGer  Costica , Costilo (Förstemann, PN 384). Hence, 'Cost (a )'s hill.' hoga is a Latinised form of OE  hoh.