caducous
Concise Oxford English Dictionary © 2008 Oxford University Press:
caducous /kəˈdjuːkəs/
▶adjective chiefly Botany (of an organ or part) easily detached and shed at an early stage.
– origin C17 (in the sense ‘epileptic’): from L. caducus ‘liable to fall’ (from cadere ‘to fall’) + -ous.
'caducous' also found in these Oxford entries:

