Speak about Erato? (5)
I believe the answer is:
orate
'speak' is the definition.
(orating is a kind of speaking)
'about erato?' is the wordplay.
'about' is an anagram indicator.
'erato' anagrammed gives 'ORATE'.
(Other definitions for orate that I've seen before include "Pontificate" , "Speak in florid style" , "Give speech" , "Make a formal speech" , "Speak formally" .)