What does the cryptic crossword clue "Troublemaker running round upset teacher is put in detention (8)" mean?

The wordplay uses an anagram. IMP (synonym="‘troublemaker’") + RIS (synonym="RIS") + ON (synonym="‘running’") = IMPRISON The answer is IMPRISON.

Troublemaker running round upset teacher is put in detention (8)

Guardian Cryptic #29558 | 19 Down | 2024-12-05 flower