field (n.)youdaoicibaDictYouDict
Old English feld "plain, pasture, open land, cultivated land" (as opposed to woodland), also "a parcel of land marked off and used for pasture or tillage," probably related to Old English folde "earth, land," from Proto-Germanic *felthuz "flat land" (Cognates: Old Saxon and Old Frisian feld "field," Old Saxon folda "earth," Middle Dutch velt, Dutch veld Old High German felt, German Feld "field," but not found originally outside West Germanic; Swedish fält, Danish felt are borrowed from German; Finnish pelto "field" is believed to have been adapted from Proto-Germanic). This is from PIE *pel(e)-tu-, from root *pele- (2) "flat, to spread" (see plane (n.1)). The English spelling with -ie- probably is the work of Anglo-French scribes (compare brief, piece).

As "battle-ground," c. 1300. Meaning "sphere or range of any related things" is from mid-14c. Physics sense is from 1845. Collective use for "all engaged in a sport" (or, in horse-racing, all but the favorite) is 1742; play the field "avoid commitment" (1936) is from notion of gamblers betting on other horses than the favorite. Cricket and baseball sense of "ground on which the game is played" is from 1875. Sense of "tract of ground where something is obtained or extracted" is from 1859. As an adjective in Old English combinations, often with a sense of "rural, rustic" (feldcirice "country-church," feldlic "rural"). Of slaves, "assigned to work in the fields" (1817, in field-hand), opposed to house. A field-trial originally was of hunting dogs.
hard-bitten (adj.)youdaoicibaDictYouDict
"tough, tough in a fight," literally "given to hard biting," 1715, originally of hunting dogs, from hard (adv.) + bitten, with the past participle used actively (as in free-spoken).
hey (interj.)youdaoicibaDictYouDict
c. 1200, implying challenge, rebuttal, anger, derision; variously spelled in Middle English hei, hai, ai, he, heh. Later in Middle English expressing sorrow, or concern; also a shout of encouragement to hunting dogs. Possibly a natural expression (compare Roman eho, Greek eia, German hei, Old French hay, French eh).
Þa onswerede þe an swiðe prudeliche, `Hei! hwuch wis read of se icudd keiser!' ["St. Katherine of Alexandria," c. 1200]
In Latin, hei was a cry of grief or fear; but heia, eia was an interjection denoting joy.