|Suggested Meaning:||stream bordered with sedges , rushes|
|First element||Scots seggy ‘bordered with sedges, rushes’|
|Second element||Scots burn ‘stream”|
|Blaeu Coila (1654):||N/A|
|OS Name Books (1855-57):||Seggy Burn|
|Location:||Ordnance Survey (1885-1900)|
Scots seggy ‘bordered with sedges, rushes’ + Scots burn ‘stream’
The Ordnance Survey Namebook (1855-57) entry for Seggy Burn reads –
A small burn about 1/2 mile N.W. [North West] of Lochill and from thence runs into Black Loch.
The Authorities say that “Seg” is the Scotch name for Flags (a water plant).
Seggy – Abounding with sedges, Jamieson
The Namebook entry gives the following two offerings for the origins of the place-name element seggy.
1. Scots seg, seggie (dimunitive form) ‘flags (water plant)’
The first offering is from the local Authorities for the spelling of the name, in this case Alexander Arthur (Benston), John Weir (Lochhill) and John Young (Mid Lowes) who suggest it is from Scots seg, ‘flags (a water plant)’. The Dictionary of the Scots Language entry for seg, seggie (dimunitive)  includes a reference to the ‘yellow flag-iris, along with some broader definitions such as ‘reed or rushes in general’ as given by John Jamieson .
2. Scots seggy ‘abounding with sedges’
The second offering in the Namebook, i.e. seggy ‘abounding with sedges’ is attributed to Jamieson  which compares well with Dictionary of the Scots Language entry seggy ‘sedgy, covered in or bordered with sedge or sedges, hence marshy’ [3.]
The Seggy Burn rises in the lower slope of the hillside between Lochill and Mid Lowes (shown as Lowes in the maps above). It cuts its way down the hillside and under the A77 trunk road and on the other side of the road where the rushes align both banks, i.e. bordered with rushes, as it makes its way through the marsh land to the Black Loch.
Taking all of the above into consideration perhaps the most fitting is perhaps a combination of Jamieson’s offerings, leading to Scots seggy ‘bordered with sedges, rushes’.
It is interesting to note that the burn is named Segsy Burn on the OS Map 1854, probably a misprint since it does not match with the OS Name Book entry.
| Dictionary of the Scots Language. 2004. Scottish Language Dictionaries Ltd. |seg, seggie|
| The work of John Jamieosn (1759-1838)is regularly quoted in the Ordnance Survey Name Books and the Dictionary of the Scots Language, in particularly from his ‘An Etymological Dictionary of the Scottish Language’|
|Dictionary of the Scots Language. 2004. Scottish Language Dictionaries Ltd. |seggy|
| Dictionary of the Scots Language. 2004. Scottish Language Dictionaries Ltd.| burn|
|By Permission of National Library of Scotland|
|Images used under the terms of the Creative Commons Attribution (CC-BY) licence.|
|Map 1: Ordnance Survey, 1:25,000 maps of Great Britain – 1945-1971| Seggy Burn|
|Map 2: Ordnance Survey Maps – Six-inch 1st edition, Scotland, 1843-1882|Segsy Burn|
|Ordnance Survey Name Books|
|By Permission of Scotland’s Places|
|Ayrshire OS Name Books (1855-57) Vol. 49|Seggy Burn|