The most common and most likely answer to this crossword clue is the 10 letter word EVERYWHERE
I've seen this crossword clue in The Daily Telegraph
E
V
E
R
Y
W
H
E
R
E
More clues leading to the result EVERYWHERE
Buddy explains!
The straight part
We know that "High and low" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case high and low = everywhere.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 EVERYWHERE mean?
EVERYWHERE adverb- In or to all locations under discussion.
- In or to a few or more locations.