Tense character in Macbeth making sudden movement (6)
I believe the answer is:
twitch
'sudden movement' is the definition.
(I've seen this before)
'tense character in macbeth' is the wordplay.
'tense' becomes 't' (abbreviation used in many dictionaries).
'character in macbeth' becomes 'witch' (Shakespeare's Macbeth features three witches).
't'+'witch'='TWITCH'
'making' is the link.
(Other definitions for twitch that I've seen before include "Quiver or contract spasmodically, as eye may" , "Pang, tic" , "Move uncontrollably - watch birds" , "Quiver spasmodically as in tic" , "Pang; small noose" .)