A hypothetical subatomic particle that always travels faster than the speed of light. (noun)
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.
Use "tachyon" in a sentence
"While someone who actually has a clue what a tachyon is will feel more comfortable with the terminology, Sawyer leaves enough elbow room for non-scifi fans."
"If there is an elementary particle, or wavicle, of thought, a faster-than-light one like the tachyon might be a good candidate for the honor."
"Of course, it's the same for SF: Star Trek taught us that just about any problem whatsoever can be solved by a single talented engineer who builds a novel theory from scratch in 15 minutes and then reverses the tachyon beam."