A-team (??t?m?)n.1. A subunit of the Special Forces, usually consisting of 12 soldiers.2. Informal A group consisting of the best members of a larger group; an elite group: an A-team of foreign-policy advisers.[Informal name for A-detachment : a, first in a series + detachment.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.