Of or relating to middle age: middle-aged parents; middle-aged interests. (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 "middle-aged" in a sentence
"My adoption of the term middle-aged child has been helped by my establishing a relationship between the child, ages eight through twelve, and the Middle Ages."
"By the time I was convinced that the term middle-aged child is not an oxymoron, I also felt comfortable with the Middle Ages."
"Even in the presence of William and Harry, she called middle-aged Papa “the Boy Wonder.”"