de means 'of, off, from' dè means 'what? who?'
The most common spelling is de Buitiléir or de Buitléir in Irish Gaelic.
Caolán de Brún or Kyle de Brún would be the Irish version.As for Scottish Gaelic:
The name is of Norman rather than Gaelic origin deriving from the Norman French 'le povre', meaning 'poor'. The Irish Gaelic version is 'de Paor'.
De Donhach
de Paor
There are three Gaelic languagesAn cúigiú lá de mí Bealtaine in Irish.An còigeamh latha den Chèitein in Scottish Gaelic.Manx: ?
In Irish it's "de Bréadún"
In Irish:i gcónaí / de shíor
contento de ver vostede de novo
i gcónaí / i dtólamh / de shíor
scáth dearg [scaath de-arig]