Trefoiled

a. [f. prec. + -ED².]

  1.  (Chiefly Arch.) Ornamented with a trefoil or trefoils; formed as a trefoil (sense 3).

c. 1420.  [see prec. 3].

1815.  J. Smith, Panorama Sci. & Art, I. 154. The [window] heads being arched, are trefoiled or cinquefoiled.

1849.  Ruskin, Sev. Lamps, iv. § 27. 117. The wall in the trefoiled lights is curved.

1874.  Parker, Goth. Archit., I. iv. 144. [Early English] Doorways are generally pointed or trefoiled.

  2.  Composed of, or having leaves composed of, three leaflets, trifoliate; transf. three-lobed.

1854.  S. Thomson, Wild Fl., III. (ed. 4), 200. Trefoiled plants.

1892.  M. Stokes, Six Months in Apennines, 19. Bursting from its trefoiled shell.