lacking in vitality or intelligence; stupid, dull, or clumsy.
A little chuckle shook the Major, but he said regretfully: “Nay, I’m too gaumless.” — Georgette Heyer, The Unknown Ajax, 1959
“Did I ever look so stupid: so ‘gaumless,’ as Joseph calls it?” “Worse,” I replied, “because more sullen with it.” — Emily Brontė, Wuthering Heights, 1847
Gaumless, I reckon he was. When I saw I wasn’t getting any of his gasper I left him there. — Jeremy Gavron, The Book of Israel, 2002