fright n.

Middle English fere, from Old English fær "calamity, sudden danger, peril, sudden attack," from Proto-Germanic *feraz "danger" (source also of Old Saxon far "ambush," Old Norse far "harm, distress, deception," Dutch gevaar, German Gefahr "danger"), from PIE *pēr-, a lengthened form of the verbal root *per- (3) "to try, risk."

The sense of "state of being afraid, uneasiness caused by possible danger" developed by late 12c. Some Old English words for "fear" as we now use it were fyrhto, fyrhto; as a verb, ondrædan. Meaning "feeling of dread and reverence for God" is from c. 1400. To put the fear of God (into someone) "intimidate, cause to cower" is by 1888, from the common religious phrase; the extended use was often at first in colonial contexts:

Thus then we seek to put "the fear of God" into the natives at the point of the bayonet, and excuse ourselves for the bloody work on the plea of the benefits which we intend to confer afterwards. [Felix Adler, "The Religion of Duty," 1905]

Old English feohtan "to combat, contend with weapons, strive; attack; gain by fighting, win" (intransitive; III strong verb; past tense feaht, past participle fohten), from Proto-Germanic *fe(u)hta (source also of Old High German fehtan, German fechten, Middle Dutch and Dutch vechten, Old Frisian fiuhta "to fight"), probably from PIE *pek- (2) "to comb, to pluck out" wool or hair (source also of Lithuanian pėšti"to pluck," Greek pekein "to comb, shear," pekos "fleece, wool;" Persian pashm "wool, down," Latin pectere "to comb," Sanskrit paksman- "eyebrows, hair"). Apparently the notion is "pulling roughly," or "to tear out one another's hair." But perhaps it is from the source of Latin pugnus "fist."

Spelling substitution of -gh- for a "hard H" sound was a Middle English scribal habit, especially before -t-. In some late Old English examples, the middle consonant was represented by a yogh. Among provincial early Modern English spellings, Wright lists faight, fate, fecht, feeght, feight, feit, feyght, feyt, feort, foight.

From c. 1200 as "offer resistance, struggle;" also "to quarrel, wrangle, create a disturbance." From late 14c. as "be in conflict." Transitive use from 1690s. To fight for "contest on behalf of" is from early 14c. To fight back "resist" is recorded from 1890. Well figt þat wel fligt ("he fights well that flies fast") was a Middle English proverb.