The most common and most likely answer to this crossword clue is the 8 letter word ARMORIAL
I've seen this crossword clue in The Times
A
R
M
O
R
I
A
L
More clues leading to the result ARMORIAL
Buddy explains!
The straight part
We know that "to do with bearings" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case to do with bearings = armorial.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 ARMORIAL mean?
ARMORIAL noun- A book etc concerning heraldry, especially a collection of coats of arms.
- Of, or relating to heraldry, or to heraldic arms.
- In, or pertaining to, armor.