sigmoidaladj.
/sɪɡˈmɔɪdəl/ = sigmoid adj.
ΘΚΠ
the world > space > shape > curvature > series of curves > [adjective] > having double curve
sigmoidal1666
swan-necked1746
sigmoid1786
swan-neck1844
sigmate1887
goose-necked1907
the world > space > shape > curvature > types of curvature > [adjective] > of form of arc of circle > semicircular arc
sigmoidal1753
1666 J. Smith Γηροκομία Βασιλικὴ 233 The sigmoidal Portals hindering its return, it [the blood] must pass through the Streiner of the Lungs.
1753 Chambers's Cycl. Suppl. at Sigmoides The semicircular cavity of the cubit..is sometimes also called the sigmoidal-cavity.
1826 W. Kirby & W. Spence Introd. Entomol. IV. xxxviii. 55 The pupa..has likewise a pair of long sigmoidal ones [respiratory organs] on the back of the trunk.
1845 Encycl. Metrop. VI. 598/2 The beds of coal and accompanying strata are bent into a sigmoidal flexure.
1879 F. Rutley Study of Rocks xi. 187 At times they have a somewhat sigmoidal flexure.
Derivatives
sigˈmoidally adv. in a sigmoidal manner.
ΘΚΠ
the world > space > shape > curvature > series of curves > [adverb] > double curve
sigmoidally1854
the world > space > shape > curvature > types of curvature > [adverb] > like semicircular arc
sigmoidally1854
1854 Orr's Circle Sci.: Org. Nature I. 218 The femur..is sigmoidally bent.
1886 Geol. Mag. (N.S.) III. 150 The sigmoidally curved folds of the ganoine.
This entry has not yet been fully updated (first published 1910; most recently modified version published online March 2022).
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adj.1666