The most common and most likely answer to this crossword clue is the 5 letter word TRAMP
I've seen this crossword clue in The Times
T
R
A
M
P
More clues leading to the result TRAMP
- Loose woman putting last of opium in gin
- Long walk needing transport and parking
- Walk miles, getting snared
- Pressure on public transport, so have long walk
- Find penny on public transport vehicle in March
- Long tiring walk for vagrant
- Vagrant, male lying in bunker
- Vagrant putting pressure on public transport
- Take a walk, parking vehicle first
- Journey on foot, then miles in carriage
Buddy explains!

The straight part
We know that "Long tiring walk/vagrant" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case long tiring walk/vagrant = tramp.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 TRAMP mean?
TRAMP noun- (sometimes derogatory) A homeless person; a vagabond.
- A disreputable, promiscuous woman; a slut.
- Any ship which does not have a fixed schedule or published ports of call.
- A long walk, possibly of more than one day, in a scenic or wilderness area.
- (in apposition) Of objects, stray and intrusive and unwanted
- A metal plate worn by diggers under the hollow of the foot to save the shoe.
- To walk with heavy footsteps.
- To walk for a long time (usually through difficult terrain).
- To hitchhike.
- To tread upon forcibly and repeatedly; to trample.
- To travel or wander through.
- To cleanse, as clothes, by treading upon them in water.
- A gymnastic and recreational device consisting of a piece of taut, strong fabric stretched over a steel frame using many coiled springs as anchors.
- Any of a variety of looping or jumping instructions in specific programming languages