- Of, relating to, or proceeding from the sun: solar rays; solar physics. (adjective)
- Using or operated by energy derived from the sun: a solar heating system. (adjective)
- Determined or measured in reference to the sun: the solar year. (adjective)
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.