Dictionary.com/nugatory:

nugatory (NOO-guh-tor-ee) adjective

1. Of little or no importance; trifling.
2. Having no force; invalid. See Synonyms at vain.

Source: The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2000 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.