accidentyoudaoicibaDictYouDict
accident: [14] Etymologically, an accident is simply ‘something which happens’ – ‘an event’. That was what the word originally meant in English, and it was only subsequently that the senses ‘something which happens by chance’ and ‘mishap’ developed. It comes from the Latin verb cadere ‘fall’ (also the source of such diverse English words as case, decadent, and deciduous).

The addition of the prefix ad- ‘to’ produced accidere, literally ‘fall to’, hence ‘happen to’. Its present participle was used as an adjective in the Latin phrase rēs accidēns ‘thing happening’, and accidēns soon took on the role of a noun on its own, passing (in its stem form accident-) into Old French and thence into English.
=> case, decadent, deciduous
incidentyoudaoicibaDictYouDict
incident: [15] An incident is literally that which ‘befalls’. In common with accident and occident, and a wide range of other English words, from cadaver to occasion, it comes ultimately from Latin cadere ‘fall’. This was combined with the prefix in- ‘on’ to produce incidere ‘fall on’, hence ‘befall, happen to’. Its present participial stem incident- passed into English either directly or via French.

The use of a word that literally means ‘fall’ to denote the concept of ‘happening’ is quite a common phenomenon. It occurs also in befall and chance, and operates in other languages than English; Welsh digwydd ‘happen’, for instance, is derived from cwyddo ‘fall’.
=> accident, cadence, case, occasion
symptomyoudaoicibaDictYouDict
symptom: [16] A symptom is etymologically something that ‘happens’ – an occurrence or phenomenon. The word’s application to physiological phenomena as signs of disease is a secondary development. It comes via late Latin symptōma from Greek súmptōma ‘occurrence’, a derivative of sumpíptein ‘fall together’, hence ‘fall on, happen to’. This was a compound verb formed from the prefix sun- ‘together’ and píptein ‘fall’.
parachute (n.)youdaoicibaDictYouDict
1784 (the year the use of one first was attempted, in Paris), from French parachute, literally "that which protects against a fall," hybrid coined by French aeronaut François Blanchard (1753-1809) from para- "defense against" (see para- (2)) + chute "a fall" (see chute).
PARACHUTE, a kind of large and strong umbrella, contrived to break a person's fall from an airballoon, should any accident happen to the balloon at a high elevation. ["Supplement to the Encyclopaedia or Dictionary of Arts and Sciences," Philadelphia, 1803]
redneck (n.)youdaoicibaDictYouDict
"cracker," attested 1830 in a specialized sense ("This may be ascribed to the Red Necks, a name bestowed upon the Presbyterians in Fayetteville" -- Ann Royall, "Southern Tour I," p.148), from red (adj.1) + neck (n.). According to various theories, red perhaps from anger, or from pellagra, but most likely from mule farmers' outdoors labor in the sun, wearing a shirt and straw hat, with the neck exposed. Compare redshanks, old derogatory name for Scots Highlanders and Celtic Irish (1540s), from their going bare-legged.

It turns up again in an American context in 1904, again from Fayetteville, in a list of dialect words, meaning this time "an uncouth countryman" ["Dialect Notes," American Dialect Society, Vol. II, Part VI, 1904], but seems not to have been in widespread use in the U.S. before c. 1915. In the meantime, it was used from c. 1894 in South Africa (translating Dutch Roinek) as an insulting Boer name for "an Englishman."
Another common Boer name for an Englishman is "redneck," drawn from the fact that the back of an Englishman's neck is often burnt red by the sun. This does not happen to the Boer, who always wears a broad-brimmed hat. [James Bryce, "Impressions of South Africa," London, 1899]