The most common and most likely answer to this crossword clue is the 8 letter word PYRIDINE
I've seen this crossword clue in The Times
P
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More clues leading to the result PYRIDINE
Buddy explains!
The straight part
We know that "pungent liquid" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case pungent liquid = pyridine.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.
Crossword Answer definitions
PYRIDINE noun- Any of a class of aromatic heterocyclic compounds containing a ring of five carbon atoms and an nitrogen atom; especially the simplest one, C5H5N.