What does the cryptic crossword clue "Part of a chair Starmer’s broken (7)" mean?

The definition is "Part of a chair". The wordplay uses an anagram. anagram of STARMER = ARMREST; definition: "Part of a chair" The answer is ARMREST.

Part of a chair Starmer’s broken (7)

Guardian Cryptic #29465 | 4 Down | 2024-08-19 flower