Not accepted or recognized: an unacknowledged inventor; an unacknowledged greeting. (adjective)
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 "unacknowledged" in a sentence
"Not coincidentally, this is the group most likely to become the target of the contempt and thus the very public venom of extremists on the far-right and the far-left, working in unacknowledged but full concert, keen to neutralize people they see as spineless, bloodless sell-outs."
"How many more servicemen were captured by the enemy and remain unacknowledged?"
"That challenge to US nuclear policies took the form of the “nuclear freeze,” a movement that contributed in unacknowledged ways to the eventually successful goal of halting the insane US-Soviet nuclear arms race."