Also 6 trayfle, 9 treffle. [a. F. trèfle (16th c. treffle, 1314 tresfle, in Hatz.-Darm.):pop.L. *trifolum for cl.L. trifolium.]
† 1. = TREFOIL 1. Obs.
1510. Stanbridge, Vocab. (W. de W.), D ij b. Trifolium, trefle grasse.
1527. Andrew, Brunswykes Distyll. Waters, K j. Trayfles, Trifolium in latyn.
2. Mil. A mine having three chambers: see quots.
1756. Manningham, Compl. Treat. Mines, 1045 [contains full description and figures].
1853. Stocqueler, Milit. Encycl., Trefle (Trefoil), a term used in mining, from the similarity of the figure to trefoil. The simple trefle has only two lodgments; the double trefle, four; and the triple one, six.
1877. Knight, Dict. Mech., Trefle (Fortification), a mine with three chambers, like a trefoil.
3. A figure or arrangement like that of a triple leaf: = TREFOIL 3.
1877. Coues & Allen, N. Amer. Rod., 151. Anterior lower molar of 3 to 8 prisms, of which the anterior forms an irregular treffle.
1889. Pall Mall G., 3 Jan., 4/1. The placing of the Maxim gun underneath the orchestra, pointing across the ballroom . Around it was a trefle of harness and carbines.