Outlandish and unbelievable claims must be followed by exceptional evidence to be considered acceptable in rational discourse.

A person who makes a claim; a claimant. / A pretender to a royal title. / A racehorse offered for sale before a race and delivered to the buyer afterwards. / A claiming race.

plural of claimer

(archaic) third-person singular simple present indicative form of claim

(archaic) second-person singular simple present form of claim

plural of claimee

A person from whom something is claimed.