The most common and most likely answer to this crossword clue is the 8 letter word SWELLING
I've seen this crossword clue in The Sunday Telegraph
S
W
E
L
L
I
N
G
More clues leading to the result SWELLING
- Small area of London showing growth
- Squeal about fine increasing
- Women in trading as result of injury
- Growth of flowers well in garden
- Around spring grass is growing
- Inflated part shown by fashionable figure in government
- Burgeoning retail activity taking in women
- Finely penned chorus increasing in volume
- Expanding trade in which wife invested
Buddy explains!

The straight part
We know that "Expanding" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case expanding = swelling.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 SWELLING mean?
SWELLING verb- To become bigger, especially due to being engorged.
- To cause to become bigger.
- To grow gradually in force or loudness.
- To raise to arrogance; to puff up; to inflate.
- To be raised to arrogance.
- To be elated; to rise arrogantly.
- To be turgid, bombastic, or extravagant.
- To protuberate; to bulge out.
- The state of being swollen.
- Anything swollen, especially any abnormally swollen part of the body.
- A rising, as of passion or anger.