The most common and most likely answer to this crossword clue is the 13 letter word PRETTY-PRETTY
I've seen this crossword clue in The Times
P
R
E
T
T
Y
-
P
R
E
T
T
Y
More clues leading to the result PRETTY-PRETTY
Buddy explains!

The straight part
We know that "Overly embellished" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case overly embellished = pretty-pretty.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 PRETTY-PRETTY mean?
PRETTY-PRETTY noun- Knick-knack; trinket