Early-attested site in the Parish of Holme St Cuthbert
- Ethersyde 1538 MinAcct 1604 DKRxxxviii
- Eddersyde 1581–97 CW(OS)x
- Ederside 1605 LRMB
- Etherside 1721–34 CWiii
This doubtless gets its name from the stream which runs into Black Dub. v. ǣdre, 'watercourse,' and sīde . The dental stop d not infrequently becomes spirant ð before r , as in dial. lether for standard English 'ladder.'