Definition

1. Adjective:

   • Denoting a quantity consisting of 20 items or units: Used to describe a group or amount that totals twenty.

2. Noun:

   • The cardinal number that is the sum of nineteen and one: The number 20, represented by the symbol "20" or the Roman numeral "XX".
   • (Genetics) Normal complement of sex chromosomes in a female: In genetics, this refers specifically to the pair of X chromosomes (XX) that is typical in female mammals, determining biological sex.

Usage Examples

• Adjective:

  • She bought xx apples for the recipe. (She bought twenty apples.)
  • The team consists of xx members. (The team has twenty members.)

• Noun (Number):

  • The answer on the board was xx. (The answer was twenty.)
  • He scored xx points in the game. (He scored twenty points.)

• Noun (Genetics):

  • Humans with an xx chromosome pattern are typically female.
  • The xx genotype is one of the fundamental determinants of sex in many species.

Advanced Usage

• In formal or technical writing: "XX" is often used in Roman numeral form to denote the number twenty, especially in outlines, copyright dates, or formal titles.
  • Chapter XX of the book discusses advanced theories.
• In genetics and biology: The term is used precisely to describe chromosomal sex.
  • The study focused on gene expression in XX individuals.

Variants and Related Words

• Twentieth (adj., n.): Constituting number twenty in a sequence; the ordinal form of twenty.
  • This is the twentieth anniversary.
• Score (n.): An archaic or literary term for a group of twenty.
  • "Four score and seven years ago..." (Eighty-seven years ago...)
• XY (n.): The normal complement of sex chromosomes in a male.

Synonyms

• Twenty: The word form of the number.
• A score: (Archaic/Literary) A group of twenty.

Related Phrases

• Double X: An informal way to refer to the female sex chromosome pair.
• XX/XY system: The common chromosomal sex-determination system in mammals.

Notes on Usage

• In most general contexts (mathematics, counting), "twenty" is the standard word. "XX" as a standalone word for the number is rare outside of specific symbolic uses (like Roman numerals).
• In genetics, "XX" is a standard scientific term and is not typically replaced by the word "twenty." It is read as "X X" or "double X."
• This entry primarily covers the symbolic/numeric and genetic uses of "xx." It is distinct from its use as a placeholder (e.g., "Size: XXL") or a mark for obscenity.

Adjective

1. denoting a quantity consisting of 20 items or units

Noun

1. (genetics) normal complement of sex chromosomes in a female
2. the cardinal number that is the sum of nineteen and one