The word "of"
What a complicated word to use. Go to the dict.cc website to see the German English translation. Maybe this will help some!
Begin here
Holy
(adj): Sacred, divine, blessed.
Holiday: a holy or festive day; a day off, vacation (also sacred)
Expressions: Holy Cow! Literally true in India.
Ex: Holly Mackerel! Delicious, healthy and full of mercury.