A double falciform ejection of water vapour from under the kettlelid at both sides simultaneously.
"Ulysses" by James Joyce
Falciform: curved like a sickle.
"Explanation of Terms Used in Entomology" by John. B. Smith
H. The iliac part of the fascia lata; h, the upper cornu of its falciform process.
"Surgical Anatomy" by Joseph Maclise
They also are falciform, but one extremity is rounded, the other pointed.
"Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 3" by Various