The Collaborative International Dictionary of English v.0.48:

Trefle \Tre"fle\, n. [F. tr['e]fle. See Trefoil.] (Fort.)
   A species of time; -- so called from its resemblance in form
   to a trefoil.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Tr'efl'e \Tr['e]`fl['e]"\, a. [F. tr['e]fl['e]. See Trefoil.]
   (Her.)
   Having a three-lobed extremity or extremities, as a cross;
   also, more rarely, ornamented with trefoils projecting from
   the edges, as a bearing.
   [1913 Webster]