Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Middle-aged \Mid"dle-aged`\, a. Being about the middle of the ordinary age of man; early in the century, it was considered between 30 and 50 years old, but by the end of the 19th centruy it was considered as 40 to 60.
Wiktionary
a. of, or relating to middle age; neither old nor young
WordNet
adj. being roughly between 45 and 65 years old
Usage examples of "middle-aged".
Lee looked up and saw a strong middle-aged man in a black leather jacket, a beeper and a Buck knife and a cell on his belt line, with a younger white dude, also in a leather, had a cocky walk, coming toward him.
A frowning middle-aged woman with conspicuously rouged cheeks, chunky bifocal glasses.
Carrying his penis in his hand to shield it from the sharp metal, Vaughan climbed into the front seat and began to draw the outline of his penis against the instrument panel and centre arm-rest, marking out the erotic focus of a crash or sex act, celebrating the marriage of his own genitalia and the skull-shattered dashboard binnacle against which this middle-aged woman dentist had died.
One person, Grace Birk, a middle-aged woman who worked at the bank, took three, and a man stepped down from the curb to help her carry them without crushing them.
Point could have been any little middle-aged bourgeoise whom one meets shopping in the street.
There was one more rider, a middle-aged black man with his feet lashed to the stirrups and his hands cuffed before him, with the chain of the handcuffs through a ring on the horn of his saddle.
Another pressure door dilated, and a big balding middle-aged man stepped out, with small alert eyes on either side of a long sharp nose.
If I can do it with this middle-aged dumpy body of mine, then someone as fit as you are should have no trouble at all.
He looked up as the door opened and Professor van Duyl came in, followed by a stocky, middle-aged man bearing a tray set neatly with a large coffee pot, milk, sugar and a selection of mugs.
Dwayne was wondering how long his attack of echolalia was likely to last, and Patty Keene had to find out if her brand-newness and prettiness and outgoing personality were worth a lot to a sweet, sort of sexy, middle-aged old Pontiac dealer like Dwayne.
He was a yeoman of the ewery, a middle-aged man who had come over from Spain when Katherine was married.
Junior was there, with a fattish, middle-aged man with wide-set pale eyes and thin lips like a chimpanzee.
Allard, as Fayle now saw him, could be properly described as middle-aged.
Herr Fest, a cheerful middle-aged associate from the Institute, had made the arrangements and offered to come along in the capacity of tour guide.
Trevor Stone of Gen-Dyn was a brawny middle-aged Englishman, a Gamer before Dream Park erected the Domes.