A person 50 years old, or in his or her fifties.
Of or characteristic of a person in his or her fifties.
[From Latin quīnquāgēnārius, containing fifty, from quīnquāgēnī, fifty each, from quīnquāgintā, fifty; see penkwe in Indo-European roots.]
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.
a person between 50 and 59 years old
1. being between 50 and 59 years old
2. of or relating to a quinquagenarian
[C16: from Latin quinquāgēnārius containing fifty, from quinquāgēnī fifty each]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
quin•qua•ge•nar•i•an(ˌkwɪŋ kwə dʒəˈnɛər i ən, ˌkwɪn-)
a person who is 50 years old or between 50 and 60.
[1560–70; < Latin quīnquāgēnāri(us) containing fifty quīnquāgēn(ī) fifty each]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.