Sluggish mover rose to it's movements (8)
I believe the answer is:
tortoise
'sluggish mover' is the definition.
'tortoise' can be an answer for 'mover' (I have seen 'Slow mover ' mean 'tortoise' so perhaps 'mover' could also mean 'tortoise'). I'm not certain of the 'sluggish' bit.
'rose to it's movements' is the wordplay.
'movements' indicates anagramming the letters (I've seen 'movement' mean this (letters move around)).
'rose'+'to'+'it'='rosetoit'
'rosetoit' with letters rearranged gives 'TORTOISE'.
Can you help me to learn more?
(Other definitions for tortoise that I've seen before include "Mobile home owner?" , "Shelled creature" , "Slow reptile that raced a hare" , "Turtle-like reptile" , "One that kept leading Achilles" .)