The most common and most likely answer to this crossword clue is the 4 letter word JUBE
J
U
B
E
Buddy explains!
The straight part
We know that "sweet, in Invercargill" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sweet, in invercargill = jube.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 JUBE mean?
JUBE noun- A type of gelatine-based confection; its ingredients and consistency vary between countries.
- A rood screen.
- An open drainage channel of a type common in Tehran.