What speakers mean by it now
In current English, free covers several related ideas rather than one tight definition. A person may be free of slavery, prison, or another person’s will. A road may be free of blockage. Time may be free of appointments. A sample may be free of charge. The same adjective can mark political independence, artistic looseness, or a generous hand with money. The verb to free travels with it: to release, to rid, to make something available.
The later commercial sense, the one that prices a gift at zero, is not the oldest. For as long as English has been written down, the heart of the word has been the opposite of bondage.
How English received it
The origin of the word free is a native Germanic inheritance, not a loan from French or Latin. Middle English fre (southern copies sometimes write vreo) continues Old English frēo, also spelled frīo, freoh, frioh, and friġ. The Oxford English Dictionary places the earliest known use in the Old English period, before 1150. Both the adjective and the verb are already in the record. Beside frēo stood frēogan or frēon, which could mean to manumit a person and, in the same period, to love or to treat with honor.
The West Germanic ancestor is reconstructed as *frī, from Proto-Germanic frijaz. Close relatives still sit in the neighboring languages: German frei, Dutch vrij, Old Frisian frī, Gothic freis. Old English also kept nouns that modern speakers no longer feel as kin: frēod for affection or peace, friga for love, friðu for peace and personal security. Friend belongs to the same family. Old English frēond is, in origin, a present participle: one who loves.
The older root
Behind the Germanic adjective is a Proto-Indo-European form reconstructed as priHós or priyos, meaning dear or beloved, from a root pri- / preyH- that had to do with loving and pleasing. Sanskrit priya still means dear. Avestan friia sits in the same range. Slavic relatives keep a social reading: Old Church Slavonic prijatelji is friend. The American Heritage dictionary traces the English adjective and the verb to free to that same Indo-European root prī-.
Germanic and Celtic are the branches in which a word for beloved also came to mean not enslaved. Welsh rhydd is the Celtic match. The usual account is social rather than phonetic. In a household, the people bound to the head by kinship could be named as the beloved, one’s own, as against slaves taken from outside the clan. Those kin members held legal standing that the unfree did not, so an epithet of belonging became an epithet of liberty. Latin supplies an analogy, not a source: liberi covers both free persons and the children of a house.
The path is widely accepted and still partly conjectural. The OED records another scholarly guess: that the Indo-European base may first have meant one’s own, which would make the later split into beloved in some languages and unenslaved in others easier to picture. Guus Kroonen’s Proto-Germanic dictionary glosses the starting point as something like from one’s own clan, from which free man, not a serf, developed. None of these reconstructions is a recorded Old English gloss. They are attempts to join the Sanskrit and Germanic meanings without inventing a neater story than the evidence allows.
Morphology inside English is simple. Free is not a prefix plus a hidden root. What matters is the family around it: freedom, freely, friend, the old legal and poetic noun frith, and the weekday Friday.
How the meaning stretched
By the Old English period, frēo already meant more than manumission. It could mark exemption, action of one’s own will, nobility, even a kind of joy. Compounds such as frēobearn (a free-born child) and frēomǣg (one’s own kinsman) keep the older overlap of blood and status. A rare Old English frēo for woman or wife points the same way: the dear person of the household.
After the Conquest the word kept widening by ordinary metaphor. Mid-thirteenth-century English uses it for a way clear of obstruction. Around 1300 it describes unrestrained movement and also open-handedness, the opposite of stinginess. Late in the fourteenth century it applies to animals at liberty and to a people not under foreign rule. The sense that now dominates advertising, given without cost, is recorded from the 1580s as a specialization of free of cost. Political and aesthetic uses arrive later: liberty of action or expression in the seventeenth century, art that does not keep strictly to form in the nineteenth, and free world for non-communist states from about 1950.
The verb split across the Germanic languages in a way that still shows the double inheritance. English free and German befreien keep the legal sense. German freien and Dutch vrijen mean to woo. Old Norse frja meant to love. Gothic frijon is to love. English dropped the love reading of the verb and kept the liberate one; friend is what remains of the older affection.
North Germanic is a useful caution against assuming a single survival. Old Norse did not keep frír as the usual word for unenslaved. The native term was frjáls, literally free-necked. Modern Danish, Swedish, and Norwegian fri were taken over from Low German or German, not inherited in a straight line from the old northern form.
One remnant that still names a weekday
If this history needed one concrete remnant rather than a recap, it is Friday. The weekday is Frigg’s day, and Frigg’s name is the same beloved or loving formation that once sat beside Old English frēo. The adjective that now prices a sample at zero began as a word for the people you held dear enough to count as your own.