The most common and most likely answer to this crossword clue is the 6 letter word TUNNEL
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More clues leading to the result TUNNEL
- The French crazy about taking new subway?
- One in Paris boarding fast revolutionary part of Metro?
- Fallen nutritional contents coming up in tubular passage
- Underground passage, made by peacekeepers in Tamil Nadu, has electrical lamps initially
- Let nun construct an underground passage
- Perhaps Hazel and Leonard both turned up in passage
Buddy explains!

The straight part
We know that "tubular passage" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case tubular passage = tunnel.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 TUNNEL mean?
TUNNEL noun- An underground or underwater passage.
- A passage through or under some obstacle.
- A hole in the ground made by an animal, a burrow.
- A wrapper for a protocol that cannot otherwise be used because it is unsupported, blocked, or insecure.
- A vessel with a broad mouth at one end, a pipe or tube at the other, for conveying liquor, fluids, etc., into casks, bottles, or other vessels; a funnel.
- The opening of a chimney for the passage of smoke; a flue.
- A level passage driven across the measures, or at right angles to veins which it is desired to reach; distinguished from the drift, or gangway, which is led along the vein when reached by the tunnel.
- To make a tunnel through or under something; to burrow.
- To dig a tunnel.
- To transmit something through a tunnel (wrapper for insecure or unsupported protocol).
- To insert a catheter into a vein to allow long-term use.
- To undergo the quantum-mechanical phenomenon where a particle penetrates through a barrier that it classically cannot surmount.