Exercise or basic moves embracing sweetheart (8)
I believe the answer is:
aerobics
'exercise' is the definition.
(aerobics is a kind of exercise)
'or basic moves embracing sweetheart' is the wordplay.
'moves' is an anagram indicator.
'embracing' indicates putting letters inside.
'sweetheart' becomes 'e' (the heart/centre of 'sweet').
'or'+'basic'='orbasic'
'orbasic' with letters rearranged gives 'arobics'.
'arobics' going around 'e' is 'AEROBICS'.
(Other definitions for aerobics that I've seen before include "Exercises designed to strengthen heart and lungs" , "Exercise in the gym" , "Strenuous exercises" , "Exercises designed to increase oxygen intake" , "Sort of exercises that make Boris ache badly after an hour's gone" .)