The most common and most likely answer to this crossword clue is the 7 letter word SESSION
I've seen this crossword clue in The Guardian
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More clues leading to the result SESSION
- Discordant noises after start of Society meeting
- Back row’s accommodating second sitting
- Sounds upset over special meeting
- Awful noise around Gestapo meeting
- Rows about holding second sitting
- Sitting close to actors in Noises Off’
- Sitting close to actors in Noises Off
- Rows over press-ganging school’s head for assembly
- A parliamentary term?
- Sitting with one’s half-sister arranged
Buddy explains!

The straight part
We know that "period of play" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case period of play = session.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SESSION mean?
SESSION noun- An informal gathering of musicians to play music, especially improvised jazz or a similar genre.
- A period devoted to a particular activity, e.g. the annual or semiannual periods of a legislative body (that together comprise the legislative term) whose individual meetings are also called sessions.
- A meeting of a council, court, school, or legislative body to conduct its business.
- The sequence of interactions between client and server, or between user and system; the period during which a user is logged in or connected.
- Any of the three scheduled two hour playing sessions, from the start of play to lunch, from lunch to tea and from tea to the close of play.
- The act of sitting, or the state of being seated.
- An academic term.
- To hold or participate in a jam session with other musicians.