What does the cryptic crossword clue "Perhaps buttonhole old Catholic concealed (6)" mean?

The wordplay uses a hidden word. O (synonym="old") + RC (synonym="Catholic") + HID (synonym="concealed") = ORCHID The answer is ORCHID.

Perhaps buttonhole old Catholic concealed (6)

Guardian Cryptic #29363 | 17 Across | 2024-04-22 flower