Having three unequal sides. Used of triangles.(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 "scalene" in a sentence
"The real elements are two triangles, the rectangular isosceles which has but one form, and the most beautiful of the many forms of scalene, which is half of an equilateral triangle."
"When Owen closed his eyes, he could see them doing it, one blonde and the other red-headed, climbing up and down walls in faultless scalene triangles, counting every step."
"How can anyone say that a scalene and an equilateral are really the same "kind"!"