The most common and most likely answer to this crossword clue is the 5 plus 3 letter word NERVE GAS
I've seen this crossword clue in The Times
N
E
R
V
E
G
A
S
More clues leading to the result NERVE GAS
- New Avengers agent, deadly one
- Deadly agent in The New Avengers
- Chemical weapon — face wind
- Awful weapon verges on a non-ring explosive
- Avengers may explode deadly weapon
- Spray that kills butterflies around Georgia
- Avengers dispersing poisonous substance
- Bottle with petrol in US may be used as weapon
- New Avengers weapon
- Crackpot engraves weapon
Buddy explains!
The straight part
We know that "agent, deadly one" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case agent, deadly one = nerve gas.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.