Obsessive
Definition 1 of 3
Pro Tip 1/3
Overwhelming Interest
Use 'obsessive' to describe someone's interest that consumes their thoughts and actions beyond normal. She's obsessive about her garden, spending every free moment in it.
Pro Tip 2/3
Negative Nuance
'Obsessive' often has a negative connotation, suggesting a lack of balance or control. His obsessive gaming is affecting his grades.
Pro Tip 3/3
Unhealthy Focus
'Obsessive' implies an unhealthy level of focus that may interfere with daily life. Her obsessive checking of emails disrupted her vacation.