Definition

Adjective: 1. Previously unknown; not known or heard of before: Describes something so novel, unusual, or unprecedented that it has never been known or mentioned before. 2. Extraordinary; unparalleled: Describes something remarkable to an extreme degree, often implying it is shocking or beyond normal experience.

Usage and Examples

• As an adjective modifying a noun:
  • The company achieved unheard-of success with its new product. (The level of success was unprecedented.)
  • It was unheard-of for a student to finish the exam so quickly. (Such an event was previously unknown and astonishing.)
  • They traveled to unheard-of places. (They went to locations previously unknown or not talked about.)

Advanced Usage

• Used for emphasis: Often used to stress the extreme novelty or shock value of a situation, fact, or quality.
  • The athlete's recovery was an unheard-of medical miracle.
• Can imply disapproval: Sometimes carries a connotation of being improper or scandalous because it is so unprecedented.
  • In his day, such criticism of the king was unheard-of.

Variants and Related Words

• Unprecedented (adj): Never done or known before. (Often more neutral than , which can carry more emotional weight.)
• Unparalleled (adj): Having no parallel or equal; exceptional.
• Novel (adj): New and not resembling something formerly known.

Synonyms

• Unprecedented
• Unparalleled
• Extraordinary
• Unimagined
• Unprecedented

Idioms and Fixed Phrases

• To be unheard-of: Used as a predicate adjective to describe a state of being unknown or unprecedented.
  • Such generosity is simply unheard-of in this industry.

Adjective

1. previously unknown
   • a first novel by an unheard of writer
   • developments on an unheard-of scale