So why do we call it browsing when we look through books or visit webpages, rather than grazing? I reached out, heaved the relevant volume of my trusty copy of OED off its shelf and laboriously flicked through to the right page. No of course I didn’t, I dialled it up on the computer and scrolled down the screen. One surprise is that the figurative sense of browse seems rather recent — at least, the first citation on offer is from 1870. In 1823 Charles Lamb the essayist wrote of someone in library who “browsed at will upon that fair and wholesome pasturage”, but that doesn’t seem to convey unambiguously the idea of picking at bits here and there, just feeding, and “graze” would seem to work just as well if not better. Two centuries earlier, Shakespeare had used it much in the same sense: “There is cold meat i’ th’ Caue, we’l brouz on that” (Cymbeline).
In theory, of course, grazing refers to the action of animals such as sheep which eat grass, while browsing is pulling leaves and twigs off trees as goats and deer do. I suspect this is one of those nice distinctions that in casual use has been blurred for centuries. OED seemed to be hinting at that with the remark that browse is “sometimes carelessly used for graze, but properly implying the cropping of scanty vegetation”, though in fact that seems to be a slightly different distinction, where graze is more about hoovering up the lush sward rather than casting about here and there for edible bits.
Nowadays it’s the continuous nature of herbivorous grazing that we focus on, in contrast with the feast-and-fast pattern of a carnivore that might eat once a day, once a week or even less often in some cases. “Grazing” is basically eating between meals, a little and often. OED doesn’t trouble to suggest an explanation of the browsing metaphor, perhaps it seems too obvious, but it took me a moment to realise that the visual image of browsing is surely plucking books from different shelves here and there at more or less eye level. “The perfect browser must have one possession ... a ladder; a library ladder” (1937). By the time we make the figurative leap to browsing web pages that image is pretty well concealed, even more so now that browsing a website often seems to mean no more than reading it: you can browse a single page. After all a browser is just a tool for looking at web pages, not sifting through them.
So what did a browser do before Internet Explorer, Netscape and so on? You might guess it was someone or something that browses, but apparently (and counter-intuitively) it meant someone whose job was to supply fodder to animals when their grazing was unavailable.
On the question of vetting things versus doctoring them, I have nothing to offer.