/ əbˈsesɪv; NAmE / adjective , noun
■ adjective
thinking too much about one particular person or thing, in a way that is not normal :
He's becoming more and more obsessive about punctuality.
an obsessive attention to detail
► ob·ses·sive·ly adverb :
obsessively jealous
He worries obsessively about his appearance.
■ noun
( psychology ) a person whose mind is filled with thoughts of one particular thing or person so that they cannot think of anything else