What does the cryptic crossword clue "EU nice and calm after disruption, helping to tolerate different beliefs? (10)" mean?

The wordplay uses an anagram. anagram of EU (synonym="EU") + NICE (synonym="NICE") + CALM (synonym="CALM") = ECUMENICAL The answer is ECUMENICAL.

EU nice and calm after disruption, helping to tolerate different beliefs? (10)

Guardian Cryptic #29564 | 15 Across | 2024-12-12 flower