Survey of English Place-Names

Historical Forms

• Dimoch 1086 DB Hy2 Madox 1157,1159 P

• Dimmoch 1155,1190 P c.1275 For

• Dymmoch 1291 Heref

• Dimmoc(k), Dymmoc(k), Dymmok' 1156 RBE 1160–1204 P 1211–13 Fees 1216 ClR 1220 Fees 1221 Ass 1223 ClR 1777 PR

• Dymmoke 1199 ClR 1358 Ipm 1476 Pat

• Dimmack 1217 ClR

• Dimnoc' 1221 Ass

• Dumoch', Dymioch' 1221 Eyre

• Dimoc, Dymoc, Dymok(e), Dymocke 1221 Ass 1240 Newent58–9 1316 FA 1384 BM 1730 PR

• Dimhok 1239 Lib 1248 Ass

• Dimmog 1245 Orig

• Dumok 1246–88 Misc

• Dummoc 1276 RH

• Dimmuk, Dimmuc 1252 Ipm 1276 RH

Etymology

This is apparently a Welsh name, which Ekwall supposes is a compound of Welsh  ty 'house' and moch 'swine', denoting 'pigsty', with initial D - due to lenition of t - to d - after some preceding word. But it is preferable to take the first el. as PrWelsh  *dīn 'fort' (v. dūno-), the -n - being assimilated to -m - by the following -m -.