The most common and most likely answer to this crossword clue is the 8 letter word PATERNAL
P
A
T
E
R
N
A
L
More clues leading to the result PATERNAL
- Father's prenatal exercising
- Like dad’s friend, catching a sea bird
- A bird eaten by friend of father
- A bird in China coming from father’s side
- The old man’s alert, nap having been disturbed
- Like old man‘s chum sheltering a seabird
- Mate ringing a seabird is taking protective interest
- It may be parental — or not
- Father’s friend has caged a bird
- Secretary bird almost completely protective
Buddy explains!

The straight part
We know that "protective" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case protective = paternal.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 PATERNAL mean?
PATERNAL adjective- Of or pertaining to one's father, his genes, his relatives, or his side of a family
- Fatherly; behaving as or characteristic of a father.
- Received or inherited from one's father.
- Acting as a father