n.
Any of several celestial radio sources emitting short intense bursts of radio waves, x-rays, or visible electromagnetic radiation at regular intervals, generally believed to be rotating neutron stars.
[From PULSE1, by analogy with QUASAR.]
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.