| Noun | 1. | Cycadales - primitive tropical gymnosperms abundant in the Mesozoic, now reduced to a few scattered tropical forms plant order - the order of plants class Cycadopsida, Cycadophyta, Cycadophytina, Cycadopsida, subdivision Cycadophyta, subdivision Cycadophytina - palmlike gymnosperms: includes the surviving order Cycadales and several extinct orders; possibly not a natural group; in some systems considered a class (Cycadopsida) and in others a subdivision (Cycadophytina or Cycadophyta) cycad family, Cycadaceae, family Cycadaceae - ancient palmlike plants closely related to ferns in that fertilization is by means of spermatozoids family Zamiaceae, zamia family, Zamiaceae - a family of cycads often included in the family Cycadaceae: zamias |