The most common and most likely answer to this crossword clue is the 5 letter word BRAID
B
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Buddy explains!

The straight part
We know that "thread" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case thread = braid.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 BRAID mean?
BRAID noun- A sudden movement; a jerk, a wrench.
- A weave of three or more strands of fibers, ribbons, cords or hair often for decoration.
- A stranded wire composed of a number of smaller wires twisted together
- A tubular sheath made of braided strands of metal placed around a central cable for shielding against electromagnetic interference.
- A fancy; freak; caprice.
- To make a sudden movement with, to jerk.
- To start into motion.
- To weave together, intertwine (strands of fibers, ribbons, etc.); to arrange (hair) in braids.
- To mix, or make uniformly soft, by beating, rubbing, or straining, as in preparing food.
- To reproach; to upbraid.
- Deceitful.