so as to

In order to, as in We took off our shoes so as to avoid scratching the newly finished floors. This idiom is always followed by an infinitive. For a synonym, see in order to, def. 5.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.