If letters were legs, this word might be a truncated tarantula. But aside from the faint echo of arachnid (mainly in the spelling), to my eyes this word looks more like it is in need of truncation. Perhaps don’t take the t off; then you’re left with ranche, which is a somewhat hokey-seeming olde-style spelling of ranch. Rather, dispense with the e. Or, better yet, dig the a right out of the middle and drop the e in. After all, this word sounds like someone with a certain kind of accent saying trench.
But which accent? Some say it to rhyme with ranch. The more “proper” way has it more like “tronsh”. And some people hear it – and misspell it – as trunch. That’s not a fancy spelling for trunk; it rhymes with lunch, I guess. But trunch is found in dictionaries only as an adjective meaning “short and thick” (derived from Latin truncus, which refers to the trunk of a tree) and an obsolete noun referring to a post or stake – or a truncheon (truncheon also comes from truncus, which, incidentally, at origin means “broken off” or “lopped off”). However lopped off a truncheon may be, it’s not fit for doing any cutting itself, and it’s not really related to tranches, unless you use a truncheon to aid you in depriving someone of a tranche.
Now, if you did wield a truncheon to ill effect, it would surely be a trenchant moment, but if you then wished to make the victim disappear into a trench, you wouldn’t be able to dig the trench with a truncheon or a trunk. Fair enough: none of them are cutters; all three have been cut, and all three words come from the same Latin root – the source of truncus is in turn truncare, “cut”, and that gives us not just truncate but trench as well.
But never mind trench. Our word tranche looks French. Indeed, to my eyes, tranche is a slice – of pie or cake. Well, as Pink Floyd (specifically Roger Waters) sang, “Share it fairly, but don’t take a slice of my pie.” With or without the aid of a truncheon, and whether or not at a luncheon. But what is the pie that a tranche is a slice of in English? Typically stocks or bonds or perhaps a loan: if a block of money (or paper promises) is handed over not all at once but in bits over time or to several parties, those shares are tranches. And, yes, tranche comes from a French word that ultimately comes again from truncare. Are we counting how many legs this linguistic tarantula has – or how many shares it is divided into?
Of all these different words, we may make two broad groups (or tranches, shall we say): ones in which the Latin c has retained its original /k/ sound, and ones in which it has become a fricative or even an English affricate “ch” (/tʃ/). There is a distinct phonaesthetic difference between these two tranches – one may even say there is a trench between them. The trunk side lands with a hard clunk at the back of the mouth, like knocking against wood. The trench side seems to have more of a cutting feeling: what is “ch, ch, ch” but the sound of chipping away at something? Both endings come in for a softer landing with the nasal: the tree is soft wood, or the cutting is in the ground.
But also either way, it starts with tr, which in French and Latin is a simple stop and liquid but in English with its retroflex /r/ causes the stop to become an affricate – another “ch”. Indeed, trench sounds a bit like the act of digging a trench: “trench, trench, trench.” But tranche? Well, first you have to take stock of whether you’re going to say it like “tronsh” or like “tranch” (or “trunch”), and you have to get past any echoes of trance and trash – and any spare change (to say nothing of drudge and trudge and so on) that might be lingering. And then? Well, I’ll let you say your piece.