|“David and Emily from Charles Dickens' David Copperfield”|
by Frank Reynolds.
Fast is used as an adjective, adverb, and verb. These three uses are also present in Old English: fæst (adjective), fæste (adverb), and fæstan (verb). All three uses had the sense of making or describing something as firm, secure, or fixed. The Old English words derive from Proto-Germanic *fastu-, *fasto, and *fasten. There are many cognates in other Germanic languages. The sense of abstaining from food is also present in Old English. The original meaning of holding firmly evolved to mean firm hold of oneself or firm control of one's appetites and urges. The verb fasten comes from the same root. Old English fæstnian—meaning to fix, make firm, or secure—derives from Proto-Germanic *fastinon. Now that all those meanings are firmly fixed and secure, how do we get to something that moves with great speed?
Sometime before 1200, fast added quickly and rapidly to it's litany of meanings. It's not certain when this addition occurred. It may have been one of the Old English meanings. One theory, citing the influence of Old Norse, attributes the new sense to associating the adverb fast (meaning firmly or vigorously) with run. He runs hard. He runs fast. Another theory, citing the influence of Old Danish, suggests that a fast runner is one who stays close to what he is chasing. The Old Danish adjective fast includes the meanings near to and almost. The Old Norse theory makes more sense to me but I like the imagery of the Old Danish one with the warrior fast on the heels of his fleeing foe.