One of three equal parts of a divisible whole.(noun)
Gnu Collaboartive International Dictionary of English: licensed under The Code Project Open License (CPOL)
Use "one-third" in a sentence
"This, too, in the face of the fact that only _one-third_ of the 728 victims to mobs have been _charged_ with rape, to say nothing of those of that one-third who were innocent of the charge."
"The latest collaboration--it hits stores and the web this month--is with indie style icon, model and nightlife fixture Leigh Lezark, who's best known as one-third of the New York City-based DJ trio The Misshapes."
"Today, around one-third of the English vocabulary is “French,” borrowed from one or another of its medieval and modern versions."