What does the cryptic crossword clue "Undisciplined brat, heiress in Trollope's county (11)" mean?

The wordplay uses an anagram. anagram of BRAT, + HEIRESS = BARSETSHIRE The answer is BARSETSHIRE.

Undisciplined brat, heiress in Trollope's county (11)

Times Cryptic #28608 | 1 Down | 2023-05-20 flower