Join in an animated tango (3,2)
I believe the answer is:
tag on
'join' is the definition.
(thesaurus)
'an animated tango' is the wordplay.
'an animated' indicates an anagram.
'tango' anagrammed gives 'TAG ON'.
'in' acts as a link.
(Other definitions for tag on that I've seen before include "Finally join" , "Attach" , "Follow behind" , "Append" .)