Definition

Noun 1. A variable whose values are solutions of an equation: In mathematics, an "unknown quantity" is a symbol (often a letter like x or y) representing a number that is not yet determined but can be found by solving an equation. 2. A factor in a given situation whose bearing and importance is not apparent: A person or thing whose abilities, characteristics, or effects are not yet known or understood, making them unpredictable.

Usage Examples

• Mathematical Context:
  • In the equation 2x + 5 = 11, 'x' is the unknown quantity.
  • The scientist treated the missing data point as an unknown quantity in her model.
• Figurative/General Context:
  • The new coach is still an unknown quantity; we don't know if he can lead the team to victory.
  • The economic impact of the new policy remains an unknown quantity.

Advanced Usage

• "To be/remain an unknown quantity": This is the most common idiomatic usage, describing a person or element whose potential or nature is untested and therefore uncertain.
  • The candidate's stance on foreign policy is still an unknown quantity to most voters.

Variants and Related Words

• Unknown (adj/n): Not known; a person or thing that is unknown.
  • The virus came from an unknown source.
  • She was a complete unknown before winning the championship.

Synonyms

• Variable: (In mathematics) a symbol for an unknown number.
• Uncertainty: Something that is not known or definite.
• Wild card: An unpredictable or unforeseeable factor.
• Enigma: A person or thing that is mysterious or difficult to understand.

Related Idioms

• A question mark: Used to describe something unknown or uncertain.
  • The team's performance this season is a big question mark.
• X factor: A variable with an unknown or significant impact.
  • The team's new striker has the X factor that could win them the game.

Noun

1. a variable whose values are solutions of an equation
2. a factor in a given situation whose bearing and importance is not apparent; he's still an unknown quantity"
   • I don't know what the new man will do