noun (n)

• a person who specializes in designing architectural interiors and their furnishings(noun.person)

  Synonym:
  designer, house decorator, interior decorator, interior designer, room decorator
  

  source: wordnet30
• someone who decorates(noun.person)

  Synonym:
  ornamentalist
  

  source: wordnet30
• One who decorates, adorns, or embellishes; specifically, an artisan whose business is the decoration of houses, esp. their interior decoration.(noun)

  source: webster1913