The most common and most likely answer to this crossword clue is the 9 letter word THEREUNTO
T
H
E
R
E
U
N
T
O
More clues leading to the result THEREUNTO
- Hot tureen needs stir in addition to that
- The tiniest item of litter stores energy and oxygen in addition
- Filled with energy the littlest one has nothing in addition
- Article total includes English formally used in connection with that
- 14th? Without strong variation to that
- In addition, the soldiers and peacekeepers will get taken out initially
Buddy explains!

The straight part
We know that "in addition" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case in addition = thereunto.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 THEREUNTO mean?
THEREUNTO adverb- Thereto