/ əbˈses; NAmE / verb
1.
[ vn ] [ usually passive ] to completely fill your mind so that you cannot think of anything else, in a way that is not normal :
He's obsessed by computers.
She's completely obsessed with him.
The need to produce the most exciting newspaper story obsesses most journalists.
2.
obsess (about sth) [ v ] to be always talking or worrying about a particular thing, especially when this annoys other people :
I think you should try to stop obsessing about food.
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WORD ORIGIN
late Middle English (in the sense haunt, possess , referring to an evil spirit): from Latin obsess- besieged, from the verb obsidere , from ob- opposite + sedere sit. The current sense dates from the late 19th cent.