The most common and most likely answer to this crossword clue is the 6 plus 5 letter word ROLLER SKATE
I've seen this crossword clue in The Times
R
O
L
L
E
R
S
K
A
T
E
More clues leading to the result ROLLER SKATE
Buddy explains!
The straight part
We know that "one runs on foot" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one runs on foot = roller skate.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 ROLLER SKATE mean?
ROLLER SKATE noun- A boot having small wheels or casters attached to its sole; used for roller skating