The most common and most likely answer to this crossword clue is the 3 letter word RUG
I've seen this crossword clue in The Guardian
R
U
G
Buddy explains!

The straight part
We know that "Wrap for travelling" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wrap for travelling = rug.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 RUG mean?
RUG noun- A partial covering for a floor.
- A (usually thick) piece of fabric used for warmth (especially on a bed); a blanket.
- A kind of coarse, heavy frieze, formerly used for clothing.
- A cloak or mantle made of such a frieze.
- A person wearing a rug.
- A cloth covering for a horse.
- A dense layer of natural vegetation that precludes the growth of crops.
- The female pubic hair.
- A rough, woolly, or shaggy dog.
- A wig; a hairpiece.
- A dense growth of chest hair.
- To pull roughly or hastily; to plunder; to spoil; to tear.
- Snug; cosy