This is the 11072nd most frequent Russian word.
глупы
"Глупы" means "stupid" or "foolish" in English.
The word "глупы" is used as a predicate adjective, describing the individuals as foolish (unwise or not understanding enough).
Они были слишком глупы, чтобы понять шутку.
They were too foolish to understand the joke.
Here, "глупы" functions as a descriptive adjective referring to the decisions, indicating they were not well-thought out.
Эти решения были глупы и поспешны.
These decisions were foolish and hasty.
In this example, "глупы" acts as a nominal predicate highlighting the foolish quality attributed to specific individuals.