Y chromosome

noun, Genetics.
1.
a sex chromosome of humans and most mammals that is present only in males and is paired with an X chromosome.
Compare X chromosome.
Origin
1920-25
British Dictionary definitions for y-chromosome

Y-chromosome

noun
1.
the sex chromosome that occurs as one of a pair with the X-chromosome in the diploid cells of the males of many animals, including humans Compare X-chromosome
y-chromosome in Medicine

Y-chromosome n.
The sex chromosome associated with male characteristics, occurring with one X-chromosome in the male sex chromosome pair.

y-chromosome in Science
Y-chromosome  
The sex chromosome that is paired with an X-chromosome in males. Most of the genes on the X-chromosome determine physical attributes associated with males, such as the development of testes. See more at sex chromosome. See Note at sex.