Definify.com
Webster 1913 Edition
Rondel
1.
(Fort.)
A small round tower erected at the foot of a bastion.
[Obs.]
2.
[F.]
(a)
Same as
Rondeau
. (b)
Specifically, a particular form of rondeau containing fourteen lines in two rhymes, the refrain being a repetition of the first and second lines as the seventh and eighth, and again as the thirteenth and fourteenth.
E. W. Gosse.