The most common and most likely answer to this crossword clue is the 9 letter word PRECURSOR
I've seen this crossword clue in The Guardian
P
R
E
C
U
R
S
O
R
More clues leading to the result PRECURSOR
- Herald procures new editor, finally
- Herald opening of picture with touching on-screen presence
- Posh car takes meandering course under parking sign
- It foreshadows PR course hacked by Right
- Herald quiet about bad fellow, type falling short
- Herald procures cracking editor at last
- Page comes back with gold for herald
- Herald’s quiet errors involved protecting copper
- Herald regularly spurned flashing light on computer screen
Buddy explains!

The straight part
We know that "Herald" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case herald = precursor.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 PRECURSOR mean?
PRECURSOR noun- That which precurses: a forerunner, predecessor, or indicator of approaching events.
- One of the compounds that participates in the chemical reaction that produces another compound.
- (of intersymbol interference) Caused by the following symbol.