PITT

Youngest-ever British prime minister, d. 1806 (4)

Solution has appeared in 2 crosswords (0 across and 2 down):

• Quick crossword No 15,870 — 2021-03-19 00:00:43
  18D: One of two British prime ministers (4)
• Quick crossword No 15,402 — 2019-09-17 23:00:39
  7D: Youngest-ever British prime minister, d. 1806 (4)