(1):

(n.) One of the two divisions of organic beings formed on the distinction of male and female.

(2):

(n.) The capability in plants of fertilizing or of being fertilized; as, staminate and pistillate flowers are of opposite sexes.

(3):

(n.) One of the groups founded on this distinction.

(4):

(n.) The distinguishing peculiarity of male or female in both animals and plants; the physical difference between male and female; the assemblage of properties or qualities by which male is distinguished from female.