Obsessive

google

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early 16th century (in the sense ‘siege’): from Latin obsessio(n- ), from the verb obsidere (see obsess).

wiktionary

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obsess +‎  -ive

etymonline

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obsessive (adj.)

"of or pertaining to obsession; liable to obsess," 1911, from obsess + -ive. As a noun, "person characterized by obsession," by 1966. Related: Obsessively. Obsessive-compulsive "combining (psychological) obsessions and compulsions" is attested from 1927.