The most common and most likely answer to this crossword clue is the 9 letter word SPINELESS
I've seen this crossword clue in The Daily Telegraph
S
P
I
N
E
L
E
S
S
More clues leading to the result SPINELESS
Buddy explains!
The straight part
We know that "Yellow/invertebrate" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case yellow/invertebrate = spineless.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 SPINELESS mean?
SPINELESS adjective- Having no spine.
- Cowardly; uncourageous.