The most common and most likely answer to this crossword clue is the 9 letter word ANCILLARY
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More clues leading to the result ANCILLARY
Buddy explains!
The straight part
We know that "additional support" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case additional support = ancillary.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 ANCILLARY mean?
ANCILLARY noun- Something that serves an ancillary function, such as an easel for a painter.
- An auxiliary.
- Subordinate; secondary; auxiliary