sympathizer

[sim-puh-thahy-zer]

noun

a person who sympathizes.
Ophthalmology. an eye that exhibits ophthalmia because of disease or injury of the other.

Origin of sympathizer

First recorded in 1805–15; sympathize + -er¹

Related formsnon·sym·pa·thiz·er, noun

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Anyone considered insufficiently anti-Communist was deemed a “comsymp”—short for Communist sympathizer.
A Brief History of Wingnuts in America; From George Washington to Woodstock
John Avlon
August 17, 2014
The president considered “Lucky Lindy,” as he was derisively called, a Nazi sympathizer and a subversive.
The Fight Over America’s Entrance to WWII
Sandra McElwaine
April 7, 2013

But is Mrs. Boompointer really disaffected, and a Southern sympathizer?
Clarence
Bret Harte
"And think of how hard Dave and you worked," put in a sympathizer.
Dave Porter and His Rivals
Edward Stratemeyer
You are a well-known Northern sympathizer and I am compelled to do it.
Before the Dawn
Joseph Alexander Altsheler
"I thought you were a Spanish sympathizer, Mr. Wyman," he said.
A Voyage with Captain Dynamite
Charles Edward Rich
It created a sort of sympathy which was bad for the digestion of the sympathizer.
The Eddy
Clarence L. Cullen

1815, agent noun from sympathize.