| Noun | 1. | genus Cycas - type genus of Cycadaceae: genus of widely distributed Old World evergreen tropical trees having pinnate leaves and columnar stems covered with persistent bases of old leavesgymnosperm genus - a genus of gymnosperms cycad family, Cycadaceae, family Cycadaceae - ancient palmlike plants closely related to ferns in that fertilization is by means of spermatozoids |