The most common and most likely answer to this crossword clue is the 8 letter word BUTTRESS
I've seen this crossword clue in The Guardian
B
U
T
T
R
E
S
S
More clues leading to the result BUTTRESS
- Support objection over lock
- Prop, you said, caught by Belfast's flankers and lock
- Yet to lock in support for Notre Dame?
- Supportinserted in wobbly bust
- Objection with pressure losing initial support
- It strengthens the wall, still needs a lock
- Nonetheless, lock is a prop
- Raise barrel and lock for support
- Set up bath and lock support
- Support good queen going about old city keeping dry
Buddy explains!

The straight part
We know that "Support" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case support = buttress.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 BUTTRESS mean?
BUTTRESS noun- A brick or stone structure built against another structure to support it.
- Anything that serves to support something; a prop.
- A buttress-root.
- A feature jutting prominently out from a mountain or rock; a crag, a bluff.
- Anything that supports or strengthens.
- To support something physically with, or as if with, a prop or buttress.
- (by extension) To support something or someone by supplying evidence; to corroborate or substantiate.