Clue: Dancer, possibly Irene Short, gyrating at stag party? (8)
Answer: REINDEER
Explanation: Dancer, possibly Irene Short, gyrating at stag party? (8)
***(iren)** ("Irene", short) + **DEER** ("stag") 
*The "party" in this clue is not needed for the wordplay, so is redundant.