Definify.com
Webster 1913 Edition
Oillet
Oil′let
,Noun.
[See
Eyelet
.] (Arch.)
(a)
A small opening or loophole, sometimes circular, used in mediaeval fortifications.
(b)
A small circular opening, and ring of moldings surrounding it, used in window tracery in Gothic architecture.
[Written also
oylet
.] 