assertor

from The Collaborative International Dictionary of English v.0.48

Assertor \As*sert"or\, n. [L., fr. asserere.]
   One who asserts or avers; one who maintains or vindicates a
   claim or a right; an affirmer, supporter, or vindicator; a
   defender; an asserter.
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         The assertors of liberty said not a word. --Macaulay.
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         Faithful assertor of thy country's cause. --Prior.
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