What does the cryptic crossword clue "Dubliner having his arm in cast (8)" mean?

The definition is "Dubliner". The wordplay uses an anagram. anagram of HIS + ARM + IN = IRISHMAN; definition: "Dubliner" The answer is IRISHMAN.

Dubliner having his arm in cast (8)

Guardian Cryptic #29321 | 7 Down | 2024-03-04 flower