gormless

Concise Oxford English Dictionary © 2008 Oxford University Press:
gormless/ˈɡɔːmləs/

▶adjective Brit. informal lacking sense or initiative.

– derivatives
gormlessly adverb,
gormlessness noun.

– origin C18 (orig. as gaumless): from dial. gaum ‘understanding’ (from ON gaumr ‘care, heed’) + -less.