Now that Mark Liberman has looked at the phonology
of tighty-whitey (and tidy-whitey and tidy-widy), let's take a quick
first glance at the semantics. To simplify things, I'm going to
reduce the profusion of spellings described here
to one spelling, and in the plural (but, like briefs, with reference to an
individual object) : tighty-whities.
What makes this an interesting question is that the expression is so recent -- so far it's been traced back to 1990, and is surely a bit older than that, but its absence from the standard dictionaries and sources of information on word and phrase histories suggests that it's probably not more than twenty or so years old -- that you might not have expected it to have drifted very far semantically. It's also so (apparently) transparent that you might have expected the components of tightness and whiteness to have maintained themselves over those few years. But, as it turns out, the gloss 'men's briefs', even amended to include whiteness and tightness, doesn't really do the trick.
For a long time, there were briefs, and there were boxers, and briefs
were white, made of cotton, had fly-fronts, had no legs, and caught a
man's equipment in a pouch (hence, were "tighter" than boxers).
These are still the prototypical briefs, though for decades they've been
available in colors and in other fabrics (like silk), without
fly-fronts (these are "bikini briefs", though they aren't necessarily
minimal objects), and in generous dimensions (so, not
constricting). There's even the hybrid the "boxer brief", with
both legs and a pouch.
So the question is: which of these objects count as tighty-whities?
I think that the fly-front is still non-negotiable (so that American tighty-whities correspond to British Y-fronts): snug white cotton BIKINI briefs for men are not tighty-whities. But all the other components already seem to be negotiable, so maybe this one will become flexible too, and people will start talking about bikini tighty-whities. It's already possible to find references to loose tighty-whities, to red tighty-whities and black tighty-whities (one writer wonders whether the black ones should be called tighty-blackies), and to silk tighty-whities.
It looks like the current best gloss for tighty-whities is 'fly-front briefs', perhaps amended by 'usu. snug, white, and cotton'. The 'men's' component comes for free, given the fly-front component: fly-front briefs are intended for men, though they can of course be worn by women (for whatever reason). (There are bikini briefs made for women, though the line, if there is one, between these and panties is unclear to me. Sometimes I think that bikini briefs are just panties for men. Hey, I wear them myself, and have for decades. I'm not criticizing guys in bikini briefs.)
A further subtlety is the evaluative dimension of tighty-whities. It's not entirely clear to me whether the judgments here are directly on fly-front briefs (esp. snug white cotton ones) and the sort of men who would wear them, or whether there's an evaluative dimension to the expression tighty-whities itself. Both things are possible: sometimes judgments cut across linguistic expressions, other times they're attached to specific expressions.
I just don't know what this social world is like, in detail. I know that some American speakers now view tighty-whities as a negative, dismissive label (perhaps through association with uptight and tight-assed and even the racial tag whitey), in a way that (I think) Y-fronts just doesn't function in British English, even for people who think Y-fronts are, well, boring. I know that some people didn't used to have those judgments. I suspect that some of this is fashion in dress and some of it is fashion in language, and that it's different for different people, but I have no idea what the details are like.
zwicky at-sign csli period stanford period edu