The meaning of words change over time. But when a particular sense of a word falls out of general use, sometimes the old meaning sticks around in idiomatic and stock phrases. Such is the case with quick, which did not always mean fast, rapid.
The word comes from the Old English cwic, meaning “alive,” as in this passage from Beowulf, lines 791–794a, in which the eponymous hero intends to fight the monster Grendel to its death:
Nolde eorla hleo ænige þinga
þone cwealm-cuman cwicne forlætan,
ne his lif-dagas leod ængum
(The protector of men did not want the murderous visitor to depart alive by any means, nor did he reckon the days of his life of use to anyone)
This original sense of the word is still occasionally used, but outside of the stock phrases the quick and the dead (the living and the dead) and cut to the quick (seriously wound, a reference to living flesh and the cutting a nail down to the living tissue) it is pretty rare nowadays. And the rarity of the original meaning is demonstrated by how often these stock phrases are reanalyzed to use the “fast” meaning. The quick and the dead is often taken to mean be fast or you will die, as in the title of Sam Raimi’s 1995 gunslinger film. And cut to the quick is often erroneously used to mean get to the heart of the matter, stop beating around the bush.
The original sense appears in a few other contexts, like the phrase quick with child, meaning pregnant. This is an inversion of the original with quick child. The word quickening, once common but now pretty rare, refers to the first movements of a fetus in the womb, and it was also featured in the title of the 1991 sci-fi film Highlander II: The Quickening. What is it about quick and schlock film titles?
The original sense also survives in quicksilver, another name for mercury, a word that goes back to the Old English cwicseolfor and is a reference to the fact that drops of liquid mercury move as if they were alive (cf. mercury).
Around the year 1300, quick acquired the sense of moving, shifting and also fast, swift. The first gives us quicksand, or moving sand, and the latter is the dominant sense of the word today. The sense of quick meaning mentally agile or smart appears around 1450, although there is a single use of cwices modes or “quick mind” in surviving Old English texts, specifically in the Old English translation of Bede’s Ecclesiastical History, where the phrase corresponds to the Latin adulescens animi uiuacis (a youth of lively mind).
In a way, you can say that language is quick. It is metaphorically alive and constantly moving and changing.
“cwic,” “cwic-seolfor,” Dictionary of Old English, University of Toronto, 2007.
“quick, adj, n.1, and adv.,” “quickening, n.1,” Oxford English Dictionary, third edition, 2007.
Copyright 1997-2015, by David Wilton