1 (Infrmal British) Lacking sense or initiative; foolish.
This gormless Christmas comedy drama has a New York restaurant manager Bill Firpo (Cage), and his two con brothers, Dave (Lovitz) and Alvin (Carvey), plying their dumb klutz criminal ways. (Trapped in Paradise, Time Out)
Bryson would never leave an Iowa strip mall with so gormless and unnuanced a line as: "We left packed with knowledge and admiration." (Lionel Shriver, Let's be charitable, The Guardian, 2002)
Morris West, who indirectly helped to make this and my other books possible, by devoting an hour of his invaluable time to me when I was a young and gormless writer. (John Pickney, A Paranormal File)
Gormless began life as the English dialect word gaumless, which was altered to the modern spelling when it expanded into wider use in the late 19th century. The origins of gaumless are easy to understand; the word derives from a combination of the dialect noun gaum, meaning 'attention' or 'understanding,' and the suffix less. Gaum also functions as a verb in some dialects, where it means 'to pay attention to' and 'to understand.' An unrelated verb gaum means 'to behave in a stupid or awkward manner.' There's also a noun gaum, meaning 'a stupid doltish person.' But none of these are as commonly used nowadays as gormless, which itself is most frequently seen in British English. (MerriamWebster)
19th century variant of 18th century gaumless, from dialect gome, from Old English gom, gome, from Old Norse gaumr heed (The Free Dictionary)