ETYMOLOGY
from idio- (own, personal, private, peculiar, separate, distinct) + glottic (pertaining to language)
EXAMPLE
“…This impression he uttered with the word “pupu,” meaning a very big papa. The boy soon gave up his idioglottic endeavors, learning German before his next-born sister had reached the age of beginning speech. So that language could have no further grammatical development…”
From: Proceedings of the Royal Canadian Institute
Being a Continuation of the “Canadian Journal” of Science, Literature, and History
October, 1888, Vol. XXIV
The Development of Language, by Horatio Hale
Lexicophilia 