det ‧ ri ‧ ment /ˈdetrəmənt, ˈdetrɪmənt/ BrE AmE noun [uncountable] formal
[ Date: 1400-1500 ; Language: Latin ; Origin: detrimentum , from deterere 'to rub away' ]
harm or damage
to the detriment of something (=resulting in harm or damage to something)
He worked very long hours, to the detriment of his marriage.