Here are the possible solutions for ten years' or hundred years' event clue
Answer
Clue
Relevancy
war
Clue
Ten years' or hundred years' event
Hundred Years' ___ (which lasted less than 100 years)
rent
Clue
"Five hundred twenty-five thousand six hundred minutes" musical
Definition
to hire
santa
Clue
"Ten times ten thousand years from now, he will continue to make glad the heart of childhood" according to a New York Sun editorial of September 21, 1897