What does the cryptic crossword clue "Victoria's one abysmally low year? (5,2)" mean?

The definition is "Victoria's one". The wordplay uses an anagram. anagram of LOW YEAR = ROYALWE The answer is ROYALWE.

Victoria's one abysmally low year? (5,2)

Guardian Cryptic #29226 | 7 Across | 2023-11-13 flower