Old English feld "plain, open 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" (common West Germanic, cf. 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 outside it; Swedish fält, Danish felt are borrowed from German), from PIE *pel(e)-tu-, from root *pele- (2) "flat, to spread" (see plane (n.1)).
Finnish pelto "field" is believed to have been adapted from Proto-Germanic. The English spelling with -ie- probably is the work of Anglo-French scribes (cf. brief, piece). Collective use for "all engaged in a sport" (or, in horseracing, all but the favorite) is 1742; play the field "avoid commitment" (1936) is from notion of gamblers betting on other horses than the favorite. Field glasses attested by 1836.
"to go out to fight," 16c., from field (n.) in the specific sense of "battlefield" (Old English). The meaning "to stop and return the ball" is first recorded 1823, originally in cricket; figurative sense is from 1902. Related: Fielded; fielding.
To have a number of sex or love partners, rather than settling on one
[1936+; fr gamblers who bet on other horses than the favorites]
(Heb. sadeh), a cultivated field, but unenclosed. It is applied to any cultivated ground or pasture (Gen. 29:2; 31:4; 34:7), or tillage (Gen. 37:7; 47:24). It is also applied to woodland (Ps. 132:6) or mountain top (Judg. 9:32, 36; 2 Sam. 1:21). It denotes sometimes a cultivated region as opposed to the wilderness (Gen. 33:19; 36:35). Unwalled villages or scattered houses are spoken of as "in the fields" (Deut. 28:3, 16; Lev. 25:31; Mark 6:36, 56). The "open field" is a place remote from a house (Gen. 4:8; Lev. 14:7, 53; 17:5). Cultivated land of any extent was called a field (Gen. 23:13, 17; 41:8; Lev. 27:16; Ruth 4:5; Neh. 12:29).