Definition of "overhead projector" []

• A projector capable of projecting enlarged images of written or pictorial material onto a screen or wall from a transparency placed horizontally below the projector and lighted from underneath. (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.

• "Mr. Knappenberger, an astronomer himself, held a news conference the next day, showing an old overhead projector that could be purchased for about $30 on eBay."