This is the 14006th most frequent Russian word.
обыкновенное
Ordinary; common.
The word "обыкновенное" is used here as an adjective to describe the morning, indicating that it was regular and not unusual.
Это было обыкновенное утро.
It was an ordinary morning.
In this sentence, "обыкновенное" modifies the noun dress, suggesting that the dress is plain or typical.
У нее обыкновенное платье.
She has a simple dress.
Here, "обыкновенном" is the form used to describe the café, giving the sense that it was unremarkable or standard.