Strange dance with an eccentric (7)
I believe the answer is:
oddball
'strange' is the definition.
(I've seen this before)
'dance with an eccentric' is the wordplay.
'dance' becomes 'ball' (ball is a kind of dance).
'with' is a charade indicator (letters next to each other).
'an eccentric' becomes 'odd' (I've seen this before).
'ball' put after 'odd' is 'ODDBALL'.
(Other definitions for oddball that I've seen before include "Crank" , "Nonconformist - peculiar" , "Eccentric person (colloq.)" , "Weird" , "Unusual" .)