Dance throughout arrest, one day only (9)
I believe the answer is:
roundelay
'dance' is the definition.
(I've seen this before)
'throughout arrest one day only' is the wordplay.
I cannot really see how this works, but
'throughout' could be 'round' (synonyms) and 'round' is found within the answer.
'one' could be 'a' (a thing is one thing) and 'a' is located in the answer.
The remaining letters 'ely' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for roundelay that I've seen before include "Circle dance; simple song" , "Slow, circling medieval dance" , "Slow dance - song with refrain" , "Short, simple song" , "Slow, medieval dance, in a circle" .)