Came from - well, hardly out of the blue! (6)
I believe the answer is:
hailed
'came' is the definition.
Although both the answer and definition are past participle verbs, I cannot see how they can define each other.
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for hailed that I've seen before include "Called to or summoned - say taxi" , "Signalled and summoned, say a taxi" , "Called out to attract attention" , "Called, a cab say" , "Greeted like old Romans did Caesar" .)