### Clue: Nettle rash at first seen on priest from the east (4)
### Answer: RILE 
 ### Explanation: Definition: Nettle
 **The 1st letter of**(… at first) "rash" **plus**(seen on) **reversal of**(… from the east, in an across clue) ELI(biblical priest).
Defn: …, as a verb.