cryptophasia

English

Noun

cryptophasia (uncountable)

1. The development by twins (identical or fraternal) of a language that only they can understand.
   • 2006, Karen Gottesman, Raising Twins After the First Year: Everything You Need to Know about Bringing Up Twins - From Toddlers to Preteens, Da Capo Press, →ISBN, page 84:

     Whether it's called cryptophasia, idioglossia, autonomous language, or plain ol' twin talk, the secret language among twins has long been a source of fascination to both parents and researchers alike. According to twin statistics ...

See also

• idioglossia