This is the 6964th most frequent Polish word.
grad
"Hail" (precipitation).
Here, 'grad' is used as a noun referring to a weather phenomenon consisting of ice pellets.
Wczoraj spadł grad i uszkodził samochód.
Yesterday, hail fell and damaged the car.
In this sentence, 'grad' is metaphorically describing a large quantity or shower of awards.
Mój kuzyn został uhonorowany gradem nagród za swoją książkę.
My cousin was honored with a hail of awards for his book.
Here, 'grad' metaphorically refers to a large and quick sequence of questions.