What does Lyall mean?
From the Old Norse personal name Liulfr, whose second element is 'ulfr' ('wolf'); adapted in Scotland after Norse settlement. The first element is obscure (possibly 'lid', host/people), so only the 'wolf' element is securely attested; a separate Gaelic derivation has also been proposed.
What does Alasdair mean?
Alasdair is the Scottish Gaelic form of Alexander, “defender of the people.”