The most common and most likely answer to this crossword clue is the 10 letter word INVARIABLE
I
N
V
A
R
I
A
B
L
E
Buddy explains!
The straight part
We know that "Constant /broadcast" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case constant /broadcast = invariable.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 INVARIABLE mean?
INVARIABLE noun- Something that does not vary; a constant.
- Not variable; unalterable; uniform; always having the same value.
- Constant.
- (by extension, grammar, of a word, or a grammatical class) That cannot undergo inflection, conjugation or declension.