The most common and most likely answer to this crossword clue is the 6 letter word TUCKER
I've seen this crossword clue in The Times
T
U
C
K
E
R
Buddy explains!

The straight part
We know that "Victorian lunchbo" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case victorian lunchbo = tucker.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 TUCKER mean?
TUCKER noun- One who or that which tucks.
- Food.
- Work that scarcely yields a living wage.
- To tire out or exhaust a person or animal.
- Lace or a piece of cloth in the neckline of a dress.
- A fuller; one who fulls cloth.