The most common and most likely answer to this crossword clue is the 7 letter word LOYALTY
I've seen this crossword clue in Independent
L
O
Y
A
L
T
Y
More clues leading to the result LOYALTY
- Look wise in speech about key allegiance
- Republican shunned by monarchy left instead to committed following
- Allegiance with kings and queens starting to switch sides
- Allegiance changing sides in The King’s Head?
- Kings and queens changing sides at first don’t show it
- Faithful conduct shown by princes, say, after changing sides initially
- Allegiance shown the Tudors, say, when changing sides?
- Fidelity of commission primarily requiring change of sides
- What devoted followers show ruling family initially changing side
- Devotion to kings and queens switching directions
Buddy explains!

The straight part
We know that "Fidelity" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fidelity = loyalty.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 LOYALTY mean?
LOYALTY noun- The state of being loyal; fidelity.
- Faithfulness or devotion to some person, cause or nation.