A graph (or similar chart) produced as a transparency for use with an overhead projector(noun)
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Use "viewgraph" in a sentence
"Presented with a chance to boldly revisit the future Nelson's and Bailey Hutchinson's constituents (aided and abetted by the viewgraph engineers from Alabama) gave us astronauts zooming around in a tin ball built from Shuttle spare parts and rusty Apollo-era hardware - behold our brave new world."
"But if it's just a bunch of viewgraph engineering with no real trajectory analysis for Orion+LAS, then shame on them."
"Why are there any missions on there that haven't performed their mission yet (e.g. Dawn), haven't launched yet (LRO), or aren't even much past the viewgraph stage (JWST)!"