falciform UK /ˈfæl.sɪ.fɔːm/US /ˈfæl.sɪ.fɔɹm/ adjective1 •Sickle-shaped.What announced the accomplishment of this rise in temperature? A double falciform ejection of water vapour from under the kettlelid at both sides simultaneously. — 1922 formsmore falciform · most falciform