Definition

Adjective 1. Ordinal number for four: Denoting position in a sequence as number four, following the third and preceding the fifth. 2. Constituting number four in a series: Used to identify the item in the fourth position.

Usage

• Used before a noun to indicate its position in an ordered sequence.
• Often written as "4th" in numeric form or "fourth" in text.
• Commonly used in dates, rankings, fractions, and lists.

Examples

• General Sequence:
  • She finished in 4th place in the race.
  • This is the 4th chapter of the book.
• Dates:
  • Independence Day is celebrated on the 4th of July.
• Fractions:
  • A quarter is one 4th of a whole.

Advanced Usage

• "the fourth estate": A collective term for the press and news media, seen as a distinct social or political force.
  • Journalists are often referred to as members of the fourth estate.
• "fourth dimension": A theoretical dimension beyond the three spatial dimensions, often associated with time in physics.
  • In his theory, time acts as the fourth dimension.

Variants and Related Words

• Fourthly (adverb): Used to introduce a fourth point or item.
  • Fourthly, we must consider the long-term costs.
• Fourth (noun): The ordinal number matching the number four in a series; also, one of four equal parts (a quarter).
  • He was the fourth to arrive.
  • Cut the pie into fourths.

Synonyms

• Quaternary (adj.): A formal synonym, especially used in technical contexts like geology.
  • The quaternary period is the current geologic time period.

Related Phrases

• Fourth wall (noun): In theater, film, and literature, the imaginary wall separating the performers/characters from the audience. Breaking the fourth wall involves directly addressing the audience.
  • The actor broke the fourth wall by looking at the camera and speaking to us.

Idioms

• Give someone the third degree: (Note: While "third degree" is a common idiom, there is no directly equivalent common idiom using "fourth." This is listed for contrast and clarity regarding ordinal idioms).
• On all fours: On hands and knees. (This idiom uses the cardinal number "four" and not the ordinal "fourth").

Adjective

1. coming next after the third and just before the fifth in position or time or degree or magnitude
   • the quaternary period of geologic time extends from the end of the tertiary period to the present