tenable
adjective
uk/ˈtenəbl/ usreasonable, or possible to achieve or defend:
The Board has decided that his position as chairman is no longer tenable.
a tenable approach/solution/point of view
HR
a job that is tenable for a particular period of time, or from a particular date, can be held for that period of time or from that date:
tenable from sth Applications are invited for the chair of Governors, tenable from 1 September 2011.