monomane, monomanin

listen to the pronunciation of monomane, monomanin
Немецкий Язык - Английский Язык
monomaniac
A person who is obsessed with a single thing, to the exclusion of other concerns
a person suffering from monomania
Focussed on one thing above all others
Affected with monomania, or partial derangement of intellect; caused by, or resulting from, monomania; as, a monomaniacal delusion
A person affected by monomania
{i} person who is obsessed with one thing