The most common and most likely answer to this crossword clue is the 9 letter word CARPETBAG
I've seen this crossword clue in The Times
C
A
R
P
E
T
B
A
G
More clues leading to the result CARPETBAG
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The straight part
We know that "travelling case" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case travelling case = carpetbag.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 CARPETBAG mean?
CARPETBAG noun- A traveling bag made from scraps of carpet and used primarily in the United States in the 19th century.
- To come to a place or organisation with which one has no previous connection with the sole or primary aim of personal gain, especially political or financial gain.
- Having the characteristics of carpetbaggers.