The most common and most likely answer to this crossword clue is the 8 letter word TORTOISE
I've seen this crossword clue in Financial Times
T
O
R
T
O
I
S
E
More clues leading to the result TORTOISE
- Tories to reform: one’s slow to move!
- Reactionary old lefty one occasionally sees, bit of a plodder?
- Slow mover in wrong French department
- Slow mover, old, is tucking into sweet cake
- Slow one is arriving in the end, after hill
- Wrong French river for this reptile
- Winner in race to reform Tories
- Fabulous race-winner? One hesitates to stick one’s neck out
- Reptile in store — it desperately gulps oxygen
- Slowcoach trained me and you, reportedly
Buddy explains!
The straight part
We know that "Slow one" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case slow one = tortoise.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 TORTOISE mean?
TORTOISE noun- Any of various land-dwelling reptiles, of the family Testudinidae or the order Testudines , whose body is enclosed in a shell (carapace plus plastron). The animal can withdraw its head and four legs partially into the shell, providing some protection from predators.