Definition of "collimate" [col•li•mate]

• To make parallel; line up. (verb-transitive)
• To adjust the line of sight of (an optical device). (verb-transitive)

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.

• "A slight vacuum is pulled behind an aluminized mylar plastic film to create a very large convex mirror to collimate the visual system in many aircraft simulators."
• "In fact, if the particles in the jet are fast enough, they can collimate themselves quite nicely due to relativistic effects."
• "In 2005 they used high-power ‘Luxeon’ LEDs, i.e. non-coherent sources, combined with a large Fresnel lens to collimate the non-directional light emitted, and managed two-way audio communications over a distance of 160 km (100 miles!) between mountaintops in Tasmania."