ISOBAR

Line connecting points of equal atmospheric pressure (6)

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

• Quick crossword No 16,185 — 2022-03-23 00:00:14
  16D: Line connecting points on a weather chart (6)
• Quick crossword No 15,590 — 2020-04-24 23:00:29
  2D: Line connecting points of equal atmospheric pressure (6)