1.  danger(n = noun.state) - the condition of being susceptible to harm or injury; "you are in no danger"; "there was widespread danger of disease"
is a kind of condition, status
has particulars: clear and present danger, hazardousness, perilousness, insecurity, peril, riskiness, exposure, vulnerability
Antonym: safety

2.  danger(n = noun.act) peril, risk - a venture undertaken without regard to possible loss or injury; "he saw the rewards but not the risks of crime"; "there was a danger he would do the wrong thing"
is a kind of venture
has particulars: chance, crapshoot, gamble

3.  danger(n = noun.state) - a cause of pain or injury or loss; "he feared the dangers of traveling by air"
is a kind of causal agency, causal agent, cause
has particulars: endangerment, hazard, jeopardy, peril, risk, powder keg, menace, threat
Derived form adjective dangerous₁

4.  danger(n = noun.location) - a dangerous place; "He moved out of danger"
is a kind of area, country
Derived form adjective dangerous₁

danger, n.
1 liability or exposure to harm.
2 a thing that causes or is likely to cause harm.
3 the status of a railway signal directing a halt or caution.

Idiom:
danger list a list of those dangerously ill, esp. in a hospital. danger money extra payment for dangerous work. in danger of likely to incur or to suffer from.

Etymology:
earlier sense 'jurisdiction, power': ME f. OF dangier ult. f. L dominus lord

N  danger, peril, insecurity, jeopardy, risk, hazard, venture, precariousness, slipperiness, instability, defenselessness, exposure, vulnerability, vulnerable point, heel of Achilles, forlorn hope, leap in the dark, road to ruin, faciles descensus Averni, hairbreadth escape, cause for alarm, source of danger, rock ahead, breakers ahead, storm brewing, clouds in the horizon, clouds gathering, warning, alarm, apprehension, in danger, endangered, fraught with danger, dangerous, hazardous, perilous, parlous, periculous, unsafe, unprotected &c (safe, protect), insecure, untrustworthy, built upon, sand, on a sandy basis, wildcat, defenseless, fenceless, guardless, harborless, unshielded, vulnerable, expugnable, exposed, open to, 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, unwarned, unadmonished, unadvised, unprepared, off one's guard, tottering, unstable, unsteady, shaky, top-heavy, tumbledown, ramshackle, crumbling, waterlogged, helpless, guideless, in a bad way, reduced to the last extremity, at the last extremity, trembling in the balance, nodding to its fall, threatening, ominous, illomened, alarming, explosive, adventurous, incidit in Scyllam qui vult vitare Charybdim, nam tua res agitur paries dum proximus ardet.

clear and present danger, danger line, danger sign, danger zone