The most common and most likely answer to this crossword clue is the 9 letter word HISTAMINE
I've seen this crossword clue in The Times
H
I
S
T
A
M
I
N
E
More clues leading to the result HISTAMINE
- Irritating thing this explosive, a bomb
- Staying power in short supply — hurry to swallow that chemical
- Allergic production has, in time, shifted
- The man is unfortunately absorbing one chemical bad for the body
- Greeting inmates assembled in a compound
- In haste, I’m developing something that might make you sneeze
Buddy explains!
The straight part
We know that "Irritating thing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case irritating thing = histamine.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.
What does HISTAMINE mean?
HISTAMINE noun- An amine, C5H9N3, formed by decarboxylation of histidine, that causes dilatation of capillaries, contraction of smooth muscle, and stimulation of gastric acid secretion; it is released during allergic reactions.