The most common and most likely answer to this crossword clue is the 9 letter word CATATONIC
I've seen this crossword clue in Financial Times
C
A
T
A
T
O
N
I
C
More clues leading to the result CATATONIC
- Rigid, like traffic bollard that’s holding up so long
- Senseless, not moving pet trembling in coat
- Suffering from rigidity, jazz fan needs something invigorating
- Maybe Tom needs a stimulant, being rigid?
- Insensible jazz fan needs a shot in the arm
- In a stupor, Kitty gets a boost
- Chap needs a medicine, being unable to move
- Immobile Tom maybe needs a medicine
- Immobile jazz fan given a shot in the arm
- … still giving pussy a drink
Buddy explains!

The straight part
We know that "unable to move" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case unable to move = catatonic.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 CATATONIC mean?
CATATONIC noun- A patient in a state of catatonia.
- Of, relating to, or suffering from catatonia.
- Motionless and unresponsive, as from shock; withdrawn.