- A Roman numeral representing the number 20.
From X chromosome.
- (biology) Having a female configuration of chromosomes as per the XY system.
2009, Gerald N. Callahan, Between XX and XY: Intersexuality and the Myth of Two Sexes, ISBN 1556527853, page 30:
- The group at John Hopkins, as well as many others, dropped the "true sex" policy (such as XX or XY) and adopted the "optimal gender" policy for assigning sex to sexually ambiguous children.
- (biology) Synonym of
- (clothing) Extra large, a garment size