What does the cryptic crossword clue "Rest is arranged for important person in hospital (6)" mean?

The definition is "hospital". The wordplay uses an anagram. anagram of REST (synonym="REST") + IS (synonym="IS") = SISTER The answer is SISTER.

Rest is arranged for important person in hospital (6)

Guardian Cryptic #29347 | 6 Across | 2024-04-03 flower