The most common and most likely answer to this crossword clue is the 10 letter word ONE-LEGGED
I've seen this crossword clue in The Guardian
O
N
E
-
L
E
G
G
E
D
Buddy explains!
The straight part
We know that "Needing support" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case needing support = one-legged.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 ONE-LEGGED mean?
ONE-LEGGED noun- A plant, especially a tree.
- Having only one leg.
- Of an audio signal: having a thin sound as a result of connection through only one wire of a circuit pair.