This is the 15815th most frequent Russian word.
продолжительной
Prolonged or long-lasting.
In this sentence, 'продолжительная' is used as an adjective to describe the meeting, emphasizing that it lasted for a considerable amount of time.
На работе сегодня была продолжительная встреча.
At work today there was an extended meeting.
Here, 'продолжительная' describes the walk, indicating that it was lengthy or took a long time.
После продолжительной прогулки на свежем воздухе я почувствовал усталость.
After an extended walk in the fresh air, I felt tired.
In this example, 'продолжительная' serves to characterize the task as taking a significant amount of time to complete.