What does the cryptic crossword clue "One US city hospital with a misguided notion … (3,7)" mean?

The wordplay uses an anagram. anagram of SAN (synonym="SAN") + NOTION (synonym="NOTION") + A (synonym="A") = SANANTONIO The answer is SANANTONIO.

One US city hospital with a misguided notion … (3,7)

Guardian Cryptic #29391 | 26 Across | 2024-05-24 flower