Answer: monomania

AnswerCrossword Clue
MONOMANIAIntense focus
MONOMANIAOverconcentration on one theme.
MONOMANIASingle-mindedness
MONOMANIAObsessive zeal for a single thing
MONOMANIASingular obsession
monomaniaExaggerated or obsessive enthusiasm for or preoccupation with one thing
monomaniaan abnormal obsession with a single thought or idea