descendable
/dɪˈsɛndɪbl/adjective
1 Law. Of property, an entitlement, etc.: that descends or may descend to an heir; transmissible by inheritance.
2That can move downwards.
3Capable of being descended; down which one may go. Somewhat rare.
Origin
Late 15th century; earliest use found in John Fortescue (c1397–1479), justice and political theorist. From descend + -able.