birthtongue

• birth-tongue, birth tongue

From Middle English burþe tonge, equivalent to birth +‎ tongue.

birthtongue (plural birthtongues)

1. (rare) One's first language, learnt in early childhood; native language.
   • 1880, All the Year Round, volume 25, page 203:

     In replying timidly, Anita revealed her foreign accent, which was instantly observed. “You are American, of course? No? English? Ah, how stupid I am!" Forthwith he began to talk fluently in German, though Anita saw it was not his birthtongue.

   • 1976, Albert Goldbarth, Comings Back: A Sequence of Poems, page 78:

     And now I place them, palms up, wrong five-legged beasts with their underbellies exposed, on the desk for you who have told me, in your own broken wedding of English and your birthtongue, […]

   • 1990, Anne McCaffrey, Elizabeth Moon, Sassinak:

     "No problem. Neo-Gaesh, and that's Orlen's birthtongue."

   • 1991, Jo Clayton, Wild Magic, page 48:

     Faan talked constantly to herself and to anyone who'd listen, mixing the Fadogur she was learning with her birthtongue in a hash of sound that gradually grew more comprehensible.

   • 1998, Wojciech W. Gasparski, David Botham, Action Learning, page 112:

     Other forms of cultural non-homogeneity (birthtongue or ethnic identity, for example) have, in the generally supportive nature of the group process, tended to become not only not a problem, […]

   • 2010, Robert V. S. Redick, The Ruling Sea, page 195:

     When this warning failed to cure the boys of recklessness, he made them recite the first apothegm of Tholjassan battle-dance at the start of every lesson — not just in Arquali, but also in their individual birthtongues: […]