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.
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.
The good we secure for ourselves is precarious and uncertain until it is secured for all of us and incorporated into our common life. Jane Addams
Existence is no more than the precarious attainment of relevance in an intensely mobile flux of past, present, and future. Susan Sontag
Do I wear a helmet? Ugh. I do when I'm riding through a precarious part of town, meaning Midtown traffic. But when I'm riding on secure protected lanes or on the paths that run along the Hudson or through Central Park - no, I don't wear the dreaded helmet then. David Byrne
Infinites, when considered absolutely without any restriction or limitation, are neither equal nor unequal, nor have any certain proportion one to another, and therefore, the principle that all infinites are equal is a precarious one. Isaac Newton
All progress is precarious, and the solution of one problem brings us face to face with another problem. Martin Luther King, Jr.