Definition of "magic number" []

• Any of the numbers, 2, 8, 20, 28, 50, 82, or 126, that represent the number of neutrons or protons in strongly bound and exceptionally stable atomic nuclei. (noun)
• Sports The number of wins by a leading team and losses by its closest competitor required in order for the leading team to capture a championship or secure a playoff spot. (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.