Definition

1. Adjective:
   • Being three years of age: Describing a person, animal, or sometimes an object that has reached the age of three years.

Usage

• The adjective "three-year-old" is used attributively, meaning it typically comes before a noun to describe it. Note the use of hyphens to connect the words when used as a single descriptive term before a noun.
• It describes the specific age of the subject.

Examples

• Adjective:
  • The three-year-old child is learning to ride a tricycle.
  • We adopted a three-year-old dog from the shelter.
  • This is a three-year-old whisky, aged in oak barrels.

Advanced Usage

• When used predictively (after a linking verb like 'is'), the hyphens are often omitted, and the phrase is written as "three years old."
  • Her daughter is three years old.
  • The vintage car is three years old.

Variants and Related Words

• Three-year-olds (noun, plural): Refers to a group of children or animals of that age.
  • The preschool class is for three-year-olds.
• Three years of age (noun phrase): A more formal equivalent.
  • The program is open to children three years of age.

Synonyms

• Aged three: (More formal)
• Three years of age: (Formal equivalent)

Notes on Meaning

• The term specifically denotes the age. It does not inherently describe behavior (like "terrible twos"), though it is often associated with developmental stages typical for that age group.
• It can be used literally for living beings or figuratively for objects to indicate their time since creation or vintage (e.g., a three-year-old wine).

Adjective

1. three years of age