precarious

Synonyms: ambiguous borderline chancy contingent dangerous delicate dicey dubious dynamite equivocal hairy hanging by a thread hazardous iffy impugnable indecisive insecure loaded on thin ice open out on a limb perilous problematic risky rocky rugged sensitive shaky slippery ticklish touch and go touchy uncertain unhealthy unreliable unsafe unsettled unstable unsteady unsure

Antonyms: certain definite firm stable strong sure undoubted