someone who claims a benefit or right or title
"claimants of unemployment compensation"
"he was a claimant to the throne"
One who claims; one who makes a claim.
"The insurance company sent an adjuster to interview the injured driver, who was waiting in the lobby as a potential claimant."
In plain English: A claimant is someone who asks for money or benefits they believe they are entitled to receive.
"The claimant waited patiently at the unemployment office for his hearing to begin."
The word "claimant" comes from the Old French clamant, which is derived from the Latin clāmō meaning "to cry out." It entered English as a present participle form that evolved into our modern term for someone who makes a claim.