originally       
adverb uk/əˈrɪdʒ.ən.əl.i/ us/əˈrɪdʒ.ən.əl.i/
B2 原本,起初,原先
first of all
  Originally it was a bedroom, but we turned it into a study. 这原本是间卧室,但我们把它改成了书房。 
 - More examples
 - The building was originally Victorian in design.
 - The city grew up originally as a crossing point on the river.
 - The novel was originally published in hardcover.
 - It was Bob who originally put up the idea of the exhibition.
 - New York was originally a Dutch trading post.