Star doesn't go conversing in Spanish (4)
I believe the answer is:
nova
'star' is the definition.
(I know that nova is a type of star)
I can't explain the remainder of the clue.
(Other definitions for nova that I've seen before include "Kind of star" , "Star showing a sudden temporary increase in brightness" , "It shines" , "A new flaring star" , "Star that suddenly becomes brighter for a time" .)