The most common and most likely answer to this crossword clue is the 7 letter word TANTIVY
I've seen this crossword clue in The Times
T
A
N
T
I
V
Y
Buddy explains!

The straight part
We know that "Call" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case call = tantivy.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.
Crossword Answer definitions
TANTIVY noun- A rapid gallop
- The sound of a hunting horn in imitation of a galloping horse
- To hurry off.
- At full tilt