Frigg

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."

sixth day of the week, Old English frigedæg "Friday, Frigga's day," from Frige, genitive of *Frigu (see Frigg), Germanic goddess of married love. The day name is a West Germanic translation of Latin dies Veneris "day of (the planet) Venus," which itself translated Greek Aphrodites hēmera.

Compare Old Norse frijadagr, Old Frisian frigendei, Middle Dutch vridach, Dutch vrijdag, German Freitag "Friday," and the Latin-derived cognates Old French vendresdi, French vendredi, Spanish viernes. In Germanic religion, Freya (q.v.) corresponds more closely in character to Venus than Frigg does, and some early Icelandic writers used Freyjudagr for "Friday."

A fast-day in the Church, hence Friday face (17c.) for a gloomy countenance. Black Friday as the name for the busy shopping day after U.S. Thanksgiving holiday is said to date from 1960s and perhaps was coined by those who had the job of controlling the crowds, not by the merchants; earlier it was used principally of Fridays when financial markets crashed (1866, 1869, 1873).