The most common and most likely answer to this crossword clue is the 7 letter word PRAISES
P
R
A
I
S
E
S
More clues leading to the result PRAISES
Buddy explains!

The straight part
We know that "congratulations" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case congratulations = praises.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 PRAISES mean?
PRAISES noun- Commendation; favourable representation in words
- Worship
- To give praise to; to commend, glorify, or worship.