What does the cryptic crossword clue "Lincoln to the west borders quiet ancient kingdom (5)" mean?

The definition is "kingdom". The wordplay uses a reversal. SH (synonym="‘quiet’ as an imperative") + EBA (synonym="EBA") = SHEBA The answer is SHEBA.

Lincoln to the west borders quiet ancient kingdom (5)

Guardian Cryptic #29371 | 9 Across | 2024-05-01 flower