To state or express positively; affirm: asserted his innocence.
To defend or maintain (one's rights, for example).
Assert oneself To act boldly or forcefully, especially in defending one's rights or stating an opinion.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.