The most common and most likely answer to this crossword clue is the 4 plus 3 letter word SKIP (B)
S
K
I
P
(
B
)
Buddy explains!

The straight part
We know that "A bit of height lopping" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a bit of height lopping = skip (b).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.