What does lastborn mean?
“Lastborn” is an informal noun and adjective referring to the child born after all of his or her siblings. As a noun, it can stand alone: “The lastborn is four years old.” As an adjective, it commonly appears before a family-role noun, as in “the lastborn child,” “lastborn son,” or “lastborn daughter.” The word is used in British and American English and is especially natural when discussing families, birth order, or sibling relationships. Although “youngest” can provide the same basic information in many contexts, “lastborn” emphasizes the child’s position in the family rather than simply age. It is often affectionate and conversational, but not limited to domestic or family writing. The older spelling “last-born” remains understandable and is still used. In a sentence, the term can be used for both a specific child and, in some contexts, for the youngest member of a group more generally.
A child born after all the other children in a family; the youngest child.
"Her younger brother is the lastborn of the family."
The word is informal and is often used in family and biographical contexts. “The youngest” is a more neutral alternative in many situations.
Born after all one’s siblings; youngest in the family.
"Their lastborn daughter had just started school."
Usually used before a noun such as “child,” “son,” or “daughter”; the hyphenated spelling “last-born” is also common.
The plural is uncommon; writers often use “the youngest” or “the lastborn” without a plural form when referring generally to a family position.
"The two lastborns were already friends."
A lastborn may be the youngest today, but the word captures a whole family order in a single memorable label.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does lastborn come from?
“Lastborn” is an English compound formed from “last” and “born.” “Last” has long been used in English to mean the latest or final member of a sequence, while “born” comes from the past participle of “bear.” The compound developed within English compound-word traditions that also produced related forms such as “firstborn,” “newborn,” and “stillborn.” These words share the element “born,” although they express different relationships to birth or birth order.
How lastborn is actually used
“Lastborn” is common in informal and family contexts in British and American English. The spelling “last-born” is also traditional and is sometimes preferred in formal or hyphenated usage. It can sound affectionate or descriptive rather than especially formal.
Easily confused with lastborn
A firstborn is the child born earliest in a family, whereas a lastborn is the child born latest.