### Clue: Aztec's short way back across the wilds of Utah (7)
### Answer: NAHUATL 
 ### Explanation: Definition: Aztec's
 { **Reversal of**(back) "lane"(a narrow road;way) **minus its last letter**(short) } **containing**(across) **anagram of**(the wilds of) UTAH.
Answer: The Aztecs' language.