- A person who has no siblings.
- A person raised as the sole child in a household.
- An only child is often stereotyped as spoiled.
- 1949, Frank B Gilbreth, Jr. and Ernestine Gilbreth Carey, Cheaper by the Dozen, dedication:
- To DAD
- who only reared twelve children
- To MOTHER
- who reared twelve only children
a person who has no siblings