The most common and most likely answer to this crossword clue is the 5 letter word VICES
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The straight part
We know that "defects" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case defects = vices.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 VICES mean?
VICES noun- A bad habit.
- Any of various crimes related (depending on jurisdiction) to prostitution, pornography, gambling, alcohol, or drugs.
- A defect in the temper or behaviour of a horse, such as to make the animal dangerous, to injure its health, or to diminish its usefulness.
- A mechanical screw apparatus used for clamping or holding (also spelled vise).
- A tool for drawing lead into cames, or flat grooved rods, for casements.
- A grip or grasp.
- A winding or spiral staircase.
- One who acts in place of a superior.