The most common and most likely answer to this crossword clue is the 5 letter word MOCKS
I've seen this crossword clue in The Daily Telegraph
M
O
C
K
S
More clues leading to the result MOCKS
Buddy explains!

The straight part
We know that "Rags" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case rags = mocks.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 MOCKS mean?
MOCKS noun- An imitation, usually of lesser quality.
- Mockery, the act of mocking.
- A practice exam set by an educating institution to prepare students for an important exam.
- A mockup or prototype.
- To mimic, to simulate.
- To create an artistic representation of.
- To make fun of by mimicking, to taunt.
- To tantalise, and disappoint the hopes of.
- To create a mockup or prototype of.