Irish twin
In real, traceable use. Part of the curated seed collection; community review is coming.
Meaning · English
Either of a pair of siblings born less than 12 months apart, especially if born within the same calendar year or school year or born one year apart.
Register: offensive, slang
Where it’s used:
Used
American English
Examples
I'm the oldest, my brother, Dylan, is the next oldest—my Irish twin.” “Irish twin?” “He's ten months younger, what is referred to sarcastically as an Irish twin. My parents still live in the same flat in Dublin I grew up in. I haven't been home much the last twelve years or so. How about you, darlin
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).
Common questions
What does “Irish twin” mean?
Either of a pair of siblings born less than 12 months apart, especially if born within the same calendar year or school year or born one year apart.
Is “Irish twin” formal or informal?
Irish twin is generally offensive, slang.