A collection of people or things united into a group.(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 "grouping" in a sentence
"That two groups should necessarily live up to the same standards when the grouping is the basis for the standards."
"They are all poets with distinct voices and the mix of such a grouping is always wonderful to hear."
"Then, I drop back 10 or 15%, load up a fair test, usually 10rnds. shoot three shot groups, on several days to see if the grouping is consistent enough for the purpose for which the load and rifle is intended."