'Glamour' and 'grammar' are, etymologically, the exact same word

In medieval Scots, 'grammar' - book learning in general - picked up a second sense, since the learned classes were rumored to dabble in astrology and the occult. Scots respelled it 'glamer,' a spell cast to make people see things differently, and English later borrowed that back as 'glamour.'

— Wikipedia contributors, Glamour — Etymology section