The most common and most likely answer to this crossword clue is the 11 letter word SENTIMENTAL
S
E
N
T
I
M
E
N
T
A
L
Buddy explains!

The straight part
We know that "soppy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case soppy = sentimental.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 SENTIMENTAL mean?
SENTIMENTAL adjective- Characterized by sentiment, sentimentality or excess emotion.
- Derived from emotion rather than reason; of or caused by sentiment.
- Romantic.