'angulosity' originates from Late Latin, specifically the word 'angulositas', where 'angulus' meant 'corner; angle' and the suffix '-osus' meant 'full of' (yielding English '-ous' and '-osity').

'angulositas' developed into French 'angulosité' and eventually became the modern English word 'angulosity'.

Initially, it meant the quality of being full of angles (angular quality), and later extended figuratively to describe a bony thinness in human features.