The most common and most likely answer to this crossword clue is the 8 letter word EMANATED
I've seen this crossword clue in The Daily Telegraph
E
M
A
N
A
T
E
D
More clues leading to the result EMANATED
- Issued title returned by upset duke
- Label written up, amended date issued
- Rose made arrangements to name date
- Rose might arrange a date with men
- English chap with date arranged came out
- Issued with name and date corrected
- Title spelled backwards with wrong date, it’s emerged
- Virile Cockney, an old-fashioned rocker, came forth
Buddy explains!

The straight part
We know that "came forth" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case came forth = emanated.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does EMANATED mean?
EMANATED verb- To come from a source; issue from.
- To send or give out; manifest.