Al·tair (ăl-tīr, -târ, ăltīr′, -târ′)
A very bright, variable binary star in the constellation Aquila, approximately 15.7 light years from Earth. Altair is one of the stars that make up the Summer Triangle.
[Arabic (an-nasr) aṭ-ṭā'ir, the flying (eagle) : al-, the + ṭā'ir, flying, active participle of ṭāra, to fly; see ṭyr in the Appendix of Semitic roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.