The story
- Scottish Gaelic · borrowed fromcapall“horse”
- Scots · borrowed fromcapercailzie
- English todaycapercaillie
Borrowed from Scots capercailzie (for the -z-, see Mackenzie and tailzie), a corruption of Scottish Gaelic capall (“horse”) + coille (“of the woods”).
Etymology from Wiktionary, CC BY-SA 4.0.