Nix

Nix is a common language in human cities with origins as a cipher language used to keep secrets from dragons during the War of the Dragons a millennium ago. It was adopted as the official language of the Wyrmbane Republic upon its founding and continues to be spoken today.
As a cipher language, it was designed to be confusing even if one could translate the words without knowing their meaning. Words are derived by combining smaller tokens from a large fixed set of base words to suggest a total meaning, though direct correlations are often purposely not obvious. Magical and traditional translations both often appear to be gibberish, as the literal meanings are somewhat distant from the implied meaning. Additionally, these combination words are heavily reused for many different meanings to assist in obfuscation. For example, both goats and trains could be roughly translated as "rock-horse", requiring context clues or a mutual understanding to know which the speaker means.
Nix borrows character sigils from the older language Kinscript, which itself shared sigils with Peaks and Valleys.