The most common and most likely answer to this crossword clue is the 10 plus 5 letter word ALIMENTARY CANAL
I've seen this crossword clue in Independent
A
L
I
M
E
N
T
A
R
Y
C
A
N
A
L
More clues leading to the result ALIMENTARY CANAL
- Unknown vessel in Malta, a liner at sea giving passage for fare
- A new mail entry cut important passage
- Breakdowns always occurring along this red route?
- Operate a cam internally to follow a course of lunch?
- Sparing nothing, American Nato ally bust gut
- Long-drawn-out course of dinner
- Passage may entail carnal stimulation
- Passage a claimant nearly diverted
Buddy explains!
The straight part
We know that "Breakdowns always occurring along this red route" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case breakdowns always occurring along this red route = alimentary canal.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.