A fanatic, a person with an obsession.
An insane person, especially one who suffers from a mania.
Able to be sensed by the senses or the psyche; able to be perceived.
Acting with or showing good sense; able to make good judgements based on reason, or reflecting such ability.
Characterized more by usefulness, practicality, or comfort than by attractiveness, formality, or fashionableness, especially of clothing.