Dancing rumba in shadows (5)
I believe the answer is:
umbra
'shadows' is the definition.
Although both the answer and definition are nouns, they are not in the same form of the noun.
'dancing rumba' is the wordplay.
'dancing' indicates an anagram.
'rumba' anagrammed gives 'UMBRA'.
'in' is the link.
Can you help me to learn more?
(Other definitions for umbra that I've seen before include "Black spot" , "Shadow's inner region" , "shady region" , "dark place" , "Rumba (anag.)" .)