I. əbˈses, äb- transitive verb
( -ed/-ing/-es )
Etymology: Latin obsessus, past participle of obsidēre to sit at, possess, besiege, from ob- toward, against, over + sedēre to sit — more at ob- , sit
1. obsolete : besiege , invest
2.
a. archaic : haunt , possess , beset
b. : to occupy an undue or disproportionate place in the mind of : trouble continuously in mind
he was obsessed by details
II. verb
intransitive verb
: to engage in obsessive thinking : become obsessed with an idea
they'll spend hours … obsessing about how awful we were — Marie Winn