It has been gaelicized as Leaslaoi (lass-lee) in Irish Gaelic.
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*New Answer*
Leslie may mean Holly Garden in which case is would be something like Lioschuileann which fits with the oldest spelling of the name which was Lesslyn/Lescelin. Leslie can mean two things holly garden or from the grey fortress. From the meaning grey fortress we get the spelling Liosliath, or something close to that. It's still pronounced similarly.
The Scottish Gaelic spelling is Steaphanaidh.
I know of no spelling for Clayton in Irish or Scottish Gaelic.
The Scottish Gaelic name MacEanraig would would be an equivalent.
The Irish language 'equivalent' of the Scottish Ian could be either Seán or Eoin, (forms of John). The original Scottish Gaelic spelling of Ian is Iain, incidentally.
The name Leslie doesn't have a Hebrew meaning. It only has a Scottish meaning. It comes from a Scottish place name, probably derived from Gaelic leas celyn meaning "garden of holly".The name Leslie doesn't have a Hebrew meaning. It only has a Scottish meaning. It comes from a Scottish place name, probably derived from Gaelic leas celyn meaning "garden of holly".
This name is of Scottish Gaelic origin. It comes from a Scottish surname and a place name which probably meant "garden of hollies".
The name Leslie is of Scottish origin and means "from the gray fortress" or "gray castle". It is a unisex name that has been used for both males and females.
There is no special spelling of the name in Irish or Scottish Gaelic: it would be the same as in English.
Apparently the French spelling Céline is used by the Irish even when the last name is in a Gaelic spelling.
The name Leslie is actually of Scottish Gaelic origin. It comes from a Scottish surname and a place name which meant "garden of hollies".
The closest Gaelic name is Aidan, spelled Aodhán in Irish Gaelicand Aodhan in Scottish Gaelic.
The name is not in Scottish Gaelic.