gust of wind, especially one blowing smoke down a chimney, back draught; squall. As the following quotations show, flans are not good for housewives, sailors or gardeners.
A flan cam doon the lum an’ blew The ase a’ ben the fleer [The ash all inwards onto the floor] (Banffshire Journal 25 Feb 1879).
Also tho the Wind be not so strong, there will come Flans and Blasts off the Land as to their swiftness and surprisal something like to Hurricanes (John Brand A Brief Description of Orkney, Zetland, Pightland-Firth & Caithness 1701).
The side of the boat was laid under water by a flan off Bressey Head (John Mill Diary of the Rev. John Mill, 1740-1803).
A Flann of rancid Dung steam will destroy a whole crop of those early Cucumber plants (James Justice Scots Gardiner 1754).