What does Hamish mean?
Hamish is the Scottish form of James, “supplanter.”
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.