Intro's changed round opening of Oliver Twist (7)
I believe the answer is:
torsion
'twist' is the definition.
(thesaurus)
'intro's changed round opening of oliver' is the wordplay.
'changed' indicates anagramming the letters.
'round' is an insertion indicator.
'opening of' indicates taking the first letters.
The initial letter of 'oliver' is 'o'.
'intros' with letters rearranged gives 'torsin'.
'torsin' going around 'o' is 'TORSION'.
(Other definitions for torsion that I've seen before include "Tortuous and twisted shape or position" , "Process of twisting" , "twist" , "Twisted position - no riots (anag)" , "Twisting force" .)