prī-, Proto-Indo-European root meaning "to love." In some languages (notably Germanic and Celtic) it developed derivatives with the sense "free, not in bondage," perhaps via "beloved" or "friend" being applied to the free members of one's clan (as opposed to slaves).

It forms all or part of: afraid; affray; filibuster; Frederick; free; freebooter; freedom; friend; Friday; Frigg; Godfrey; Geoffrey; Siegfried; Winfred.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit priyah "own, dear, beloved," priyate "loves;" Old Church Slavonic prijati "to help," prijatelji "friend;" Welsh rhydd "free;" Old English freo "exempt from; not in bondage, acting of one's own will," Gothic frijon "to love," Old English freod "affection, friendship, peace," friga "love," friðu "peace," Old Norse Frigg, name of the wife of Odin, literally "beloved" or "loving."

Old English feond "enemy, foe, adversary," originally present participle of feogan "to hate," from Proto-Germanic *fijand- "hating, hostile" (source also of Old Frisian fiand "enemy," Old Saxon fiond, Middle Dutch viant, Dutch vijand "enemy," Old Norse fjandi, Old High German fiant, Gothic fijands), from suffixed form of PIE root *pe(i)- "to hurt" (source also of Sanskrit pijati "reviles, scorns;" Avestan paman-, name of a skin disease; Greek pema "disaster, sorrow, misery, woe;" Gothic faian "to blame").

As spelling suggests, the word originally was the opposite of friend (n.). Both are from the active participles of the Germanic verbs for "to love" and "to hate." Boutkan says the "fiend" word was a Germanic analogical formation from the "friend" word. According to Bammesberger ["English Etymology"], "The long vowel in FIEND is regular. In FRIEND the vowel has been shortened; perhaps the shortening is due to compounds like FRIENDSHIP, in which the consonant group (-nds-) regularly caused shortening of the preceeding long vowel."

Fiend at first described any hostile enemy (male and female, with abstract noun form feondscipe "fiendship"), but it began to be used in late Old English for "the Devil, Satan" (literally "adversary") as the "enemy of mankind," which shifted its sense to "diabolical person" (early 13c.). The old sense of the word devolved to foe, then to the imported word enemy. For spelling with -ie- see field. Meaning "devotee (of whatever is indicated)," as in dope fiend, is from 1865.

"act as a friend to," 1550s, from be- + friend (n.). Related: Befriended; befriending.

Old English sped "success, a successful course; prosperity, riches, wealth; luck; opportunity, advancement," from Proto-Germanic *spodiz (source also of Old Saxon spod "success," Dutch spoed "haste, speed," Old High German spuot "success," Old Saxon spodian "to cause to succeed," Middle Dutch spoeden, Old High German spuoten "to haste"), from PIE *spo-ti-, from root *spes- or *speh- "prosperity" (source also of Hittite išpai- "get full, be satiated;" Sanskrit sphira "fat," sphayate "increases;" Latin spes "hope," sperare "to hope;" Old Church Slavonic spechu "endeavor," spĕti "to succeed," Russian spet' "to ripen;" Lithuanian spėju, spėti "to have leisure;" Old English spōwan "to prosper").

Meaning "rapidity of movement, quickness, swiftness" emerged in late Old English (at first usually adverbially, in dative plural, as in spedum feran). Meaning "rate of motion or progress" (whether fast or slow) is from c. 1200. Meaning "gear of a machine" is attested from 1866. Meaning "methamphetamine, or a related drug," first attested 1967, from its effect on users.

Speed limit is from 1879 (originally of locomotives); speed-trap is from 1908. Speed bump is 1975; figurative sense is 1990s. Full speed is recorded from late 14c. Speed reading first attested 1965. Speedball "mix of cocaine and morphine or heroin" is recorded from 1909.

also boy-friend, "favorite male companion" (with implication of romantic connection), "a woman's paramour," 1909, from boy + friend (n.). It was attested earlier in a non-romantic sense of "juvenile male companion" (1850).

Old English freondleas "friendless," also "orphan," and, as a noun, "an outlaw;" see friend (n.) + -less. Related: Friendlessly; friendlessness.

Old English freondlic "well-disposed, kindly;" see friend (n.) + -ly (1). Related: Friendlily; friendliness. As an adverb Old English had freondliche, but by 14c. as the inflections wore off in English it had become indistinguishable from the adjective. Probably owing to that it is rare in modern use; friendfully (mid-15c.) and the correct but ungainly friendlily (1670s) never caught on.

Old English freondscipe "friendship, mutual liking and regard," also "conjugal love;" see friend (n.) + -ship. Similar formation in Dutch vriendschap, German Freundschaft, Swedish frändskap.

also girl-friend, by 1859 as "a woman's female friend in youth," from girl + friend (n.). As a man's sweetheart, by 1922. She-friend was used 17c. in the same set of senses, of the mistress of a man and of a woman who is a close friend of another.

in the Facebook sense, attested from November 2007, from un- (1) "not" + friend (v.). Unfriended is at least as old as Shakespeare in the sense "friendless." A noun unfriend "enemy" is recorded from late 13c., chiefly in Scottish, and was still in use in the 19th century.