deciduous
adj.
1680s, from Latin deciduus "that which falls off," from decidere "to fall off," from de- "down" (see de-) + cadere "to fall" (see case, n.1). Originally with reference to leaves, petals, teeth, etc.; specific sense of "trees whose leaves fall off" (opposed to evergreen) is from 1778.
〔蒋〕[de-表示加强意义，cid落，-uous…的] 脱落的，(植物)每年落叶的
〔李〕[de-=off脱离；cid=to fall降；-u-;-ous a.=having the quality有……性质的→] a. having the quality of falling off at a certain time定期脱落的