assertor
as·sert
(ə-sûrt′)tr.v. as·sert·ed, as·sert·ing, as·serts
1. To state or express positively; affirm: asserted his innocence.
2. To defend or maintain (one's rights, for example).
3. To put into action boldly; employ or demonstrate: asserted her independence.
assert oneself
To act boldly or forcefully, especially in defending one's rights or stating an opinion.
as·sert′a·ble, as·sert′i·ble adj.
as·sert′er, as·ser′tor n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.