Precarious

Webster's Dictionary of the English Language

·adj Depending on the will or pleasure of another; held by courtesy; liable to be changed or lost at the pleasure of another; as, precarious privileges.

II. Precarious ·adj Held by a doubtful tenure; depending on unknown causes or events; exposed to constant risk; not to be depended on for certainty or stability; uncertain; as, a precarious state of health; precarious fortunes.