Friday
Old English Frīgedæg ‘day of Frigga’, named after the Germanic goddess Frigga, wife of the supreme god Odin and goddess of married love; translation of late Latin Veneris dies ‘day of Venus’, Frigga being equated with the Roman goddess of love, Venus. Compare with Dutch vrijdag and German Freitag .
wiktionary
From Middle English Friday, from Old English frīġedæġ. Compound of frīġe and dæġ(“day”), from Proto-West Germanic *Frījā dag, a calque of Latin diēs Veneris, via an association ( interpretātiō germānica) of the goddess Frigg with the Roman goddess of love Venus.
Compare West Frisian freed, German Low German Freedag, Friedag, Dutch vrijdag, German Freitag, Danish fredag. Old Norse Frigg (genitive Friggjar), Old Saxon Fri, and Old English Frig are derived from Proto-Germanic *Frijjō. Frigg is cognate with Sanskrit प्रिया(priyā́, “wife”). The root also appears in Old Saxon fri(“beloved lady”); in Swedish fria, in Danish and Norwegian as fri(“to propose for marriage”); a related meaning exists in Icelandic as frjá(“to love”) and similarly in Dutch vrijen(“to make love (to have sex)”).
etymonline
Friday (n.)
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).
