threat

danger, peril, insecurity, jeopardy, risk, hazard, venture, precariousness, slipperiness; instability; defenselessness, exposure (liability); vulnerability; vulnerable point, heel of Achilles; forlorn hope (hopelessness)., [Dangerous course] leap in the dark (rashness) [more]; road to ruin, faciles descensus Averni [Vergil], hairbreadth escape., cause for alarm; source of danger., [Approach of danger] rock ahead, breakers ahead; storm brewing; clouds in the horizon, clouds gathering; warning; alarm., [Sense of danger] apprehension [more].

be in danger; be exposed to danger, run into danger, incur danger, encounter danger; run a risk; lay oneself open to (liability); lean on a broken reed, trust to a broken reed; feel the ground sliding from under one, have to run for it; have the chances against one, have the odds against one, face long odds; be in deep trouble, be between a rock and a hard place., hang by a thread, totter; sleep on a volcano, stand on a volcano; sit on a barrel of gunpowder, live in a glass house., bring in danger, place in danger, put in danger, place in jeopardy, put in jeopardy; endanger, expose to danger, imperil; jeopard, jeopardize; compromise; sail too near the wind (rash)., adventure, risk, hazard, venture, stake, set at hazard; run the gauntlet (dare); engage in a forlorn hope., threaten danger; run one hard; lay a trap for (deceive).

in danger; endangered; fraught with danger; dangerous, hazardous, perilous, parlous, periculous; unsafe, unprotected (safe, protect [more]); insecure, . untrustworthy; built upon.sand, on a sandy basis; wildcat., defenseless, fenceless, guardless, harborless; unshielded; vulnerable, expugnable, exposed; open to (liable)., aux abois, at bay; on the wrong side of the wall, on a lee shore, on the rocks., at stake, in question; precarious, critical, ticklish; slippery, slippy; hanging by a thread; with a halter round one's neck; between the hammer and the anvil, between Scylla and Charybdis, between a rock and a hard place, between the devil and the deep blue sea, between two fires; on the edge of a precipice, on the brink of a precipice, on the verge of a precipice, on the edge of a volcano; in the lion's den, on slippery ground, under fire; not out of the wood(s).

warning, early warning, caution, caveat; notice (information); premonition, premonishment; prediction; contraindication, lesson, dehortation; admonition, monition; alarm., handwriting on the wall, mene mene tekel upharsin, red flag, yellow flag; fog-signal, foghorn; siren; monitor, warning voice, Cassandra, signs of the times, Mother Cary's chickens, stormy petrel, bird of ill omen, gathering clouds, clouds in the horizon, death watch., watchtower, beacon, signal post; lighthouse (indication of locality)., sentinel, sentry; watch, watchman; watch and ward; watchdog, bandog, housedog; patrol, patrolman, vedette, picket, bivouac, scout, spy, spial; undercover agent, mole, plainclothesman; advanced guard, rear guard; lookout., cautiousness.

warn, caution; forewarn, prewarn; admonish, premonish; give notice, give warning, dehort; menace (threaten); put on one's guard; sound the alarm; croak., beware, ware; take warning, take heed at one's peril; keep watch and ward (care).

warning; premonitory, monitory, cautionary; admonitory, admonitive; sematic., warned, forewarned; on one's guard (careful) [more], (cautious) [more].

in terrorem (threat).