I often say britches in informal conversation.* I’m washing a load of laundry so I’ll have clean britches to wear next week.* I wouldn’t say, “I bought some britches today”. I bought some pants today sounds better.
I’ve heard people in other parts of the US say trousers.
Do you use the words britches or trousers in certain contexts?
I’m curious if britches is a regional expression? I live in the South.
Personally, I’d never say either, but (at least in the midwest) I’ve only heard trousers (and it’s only ‘old people’ saying it). The only time I’ve ever heard britches, it’s a Briticism.
Not part of my vocabulary, and I’m also in the south. I say “pants,” “jeans,” “slacks,” or “khakis” to denote different flavors of pants.
For some reason corduroy trousers sounds better to me than corduroy pants. But I only say britches when I sing that silly song. You know, ♪Matthew, Mark, Luke and John went to bed with their trousers on. John got up in the middle of the night and said his britches were too tight…♫
Parents often admonish their kids by saying, you’re getting too big for your britches. My daughters know that expression all too well. 
I grew up in Georgia, and people said “britches” at the time. I rarely hear it anymore, but I still say it myself because it sounds naughty.
I had to vote “Other”, because I live in the UK and therefore always say “trousers”.
I’ve known some rural folks who used “britches” to refer to underwear, not pants.
Of course I say trousers: I’m British and pants are what we wear underneath!
I say britches sometimes when I use my full-blown, over the top, Texas accent.
I use the words trousers and pants interchangeably.
Only pants here. I live in the South. Britches is sort of a “joke” word. People occasionally say “trousers” but it sounds sort of pretentious.
I mostly say trousers (or jeans). I almost never say pants, that seems to me a primarily American term.
Daks, slacks, trews, and strides are also common slang my Mum used to use (and probably still does).
Britches more than trousers. It’s what I call what you call “short pants”. If I tell me wife “toss a couple pairs or britches in my suitcase” I know I’ll find my docker cargo pocket short pants when I get to my destination.
(Of course, being into Living History I have knee-britches as well but --------- )
I think of britches as an old fogey term, and trousers as a bit stuffy. Pants is a much simpler term.
My personal nomenclature for garments that cover the waist-to-ankle portion of the adult human being ranks in approximate frequency, high to low:
British people don’t use the term ‘britches’. Breeches, however, are a specific type of garment you wear to ride a horse. They differ from jodhpurs in that they wrap around your calf so they can fit snuggle inside your boot, whereas jodhpurs are ankle length for wearing with short jodhpur boots.
I only know this startling piece of info because my father was a riding wear manufacturer.
Native Californian. “Britches” sounds unspeakably hick to my ears. If another Californian said “trousers” I’d think they were a poseur (as I do when they say “whinge”).
I voted that I only said pants, but I do say slacks or jeans sometimes, if appropriate.
Britches sounds like it came from breeches which you wear to ride horses. But I don’t know if that’s it’s origin or not.
Lifelong Californian: I only say “pants.” I agree with woodstockbirdybird that “britches” sounds hick, and “trousers” sounds pretentious if you’re American. I sometimes say “jeans” or “cargos” to differentiate the types.