The most common and most likely answer to this crossword clue is the 5 plus 3 letter word TRAIL MIX
I've seen this crossword clue in The Daily Telegraph
T
R
A
I
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X
More clues leading to the result TRAIL MIX
- Snack when walking dog team around, covering miles
- Wake, taking hobnob for energy snack
- Wanderer’s one that’s fibbed about being kept in trim primarily by snack food
- Food for tramp in Spooner’s mantraps
- Scoff when rambling confession of perjurer retracted in Texas
- Spooner’s macho schemes for sustenance when walking
- Fruit and nuts I left in disorganized matrix
Buddy explains!
The straight part
We know that "sustenance when walking" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sustenance when walking = trail mix.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.