The most common and most likely answer to this crossword clue is the 12 letter word WEATHERPROOF
I've seen this crossword clue in The Daily Telegraph
W
E
A
T
H
E
R
P
R
O
O
F
Buddy explains!
The straight part
We know that "to provide elementary protection?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case to provide elementary protection? = weatherproof.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 WEATHERPROOF mean?
WEATHERPROOF verb- To make something resistant to damage caused by the weather.
- Capable of resisting damage caused by the weather.