One that magnifies, especially a magnifying glass.(noun)
A system of optical components that magnifies.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "magnifier" in a sentence
"Windows: The Windows built-in magnifier tool was designed more for aiding those with vision problems than aiding those giving presentations."
"The magnifier is a tool numismatists have in their hands all the time."
"The area acts as a "magnifier" for global warming, Zheng Guoguang, head of China Meteorological Administration, said at a meeting in Lhasa last spring."