See precarious in Webster's New World Roget's A-Z Thesaurus II
adjective
Not physically steady or firm:
rickety, shaky, tottering, tottery, unstable, unsteady, wobbly. See flexibleLacking stability:
infirm, insecure, shaky, tottering, tottery, unstable, unsteady, unsure, weak, wobbly. See change, strong
Learn more about precarious