This is the 3406th most frequent Polish word.
wystarczyło
"Was enough" or "sufficed."
In this sentence, 'wystarczyło' means 'was sufficient/enough' and emphasizes that just one glance provided the needed understanding.
Wystarczyło jedno spojrzenie, aby zrozumieć, że się zgadza.
One glance was enough to understand that it was true.
Here, 'wystarczyło' conveys that a small amount of additional time was adequate to achieve the task.
Do zakończenia projektu wystarczyło kilka dodatkowych godzin.
To complete the project, a few additional hours sufficed.
This sentence uses 'wystarczyło' to indicate that very few words were sufficient for explanation.