unindent

un- +‎ indent; Originated in the 1980s when computers made it simple for a writer to position text on a page.

unindent (third-person singular simple present unindents, present participle unindenting, simple past and past participle unindented)

1. To remove the indentation; to move a block of text closer to the left margin.

   I had to unindent the first line of each paragraph so that my essay would fit onto one side of paper.

• untinned