I am not sure about the definition of the word but look up Georgian, 33 letters, 33 sounds. Each letter has one and only one sound, which never ever changes despite the position in the word or the surrounding letters
I studied German in high school and then as an adult I traveled to India and studied Malayalam, the language of the southern-most state of Kerala. I was surprised at how similar Malayalam was to German (in terms of grammatical structure, not vocabulary) and learned that it's because of Hermann Gundert, a 19th Century German missionary who learned Malayalam (and a bunch of other Indian languages) and published its first formal grammar, more-or-less imposing German's grammatical structure onto it.