Is there a similar word to 'twain' but meaning 'three' instead of 'two'?

I would like to split something into three parts, is there a phrase I can use with similar overtones to "cleave in twain"?

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After reading the contemporary meaning of twain I couldn't look at Mark Twain the same way. –  speedyGonzales Jan 13 '12 at 8:52
What meaning? BTW, M.T. was the first man to prove the existence of god(s). –  Gangnus Jan 13 '12 at 9:42
I think it's spelled "train"... :P –  jadarnel27 Jan 13 '12 at 15:43
Cleave in trio. –  ottodidakt Feb 5 at 2:26

As far as meaning goes, you can use "cleave in three" or "cleave in thirds". More obscure and inexact is "cleave in terciles" or tertiles. The latter two words are statistical terms referring to "three [ordered] parts, each containing a third of the population" and "any one of the three groups so divided".

The rationale for "cleave in three" and "cleave in thirds" is that twain means two. In its etymology we find it " survived as a secondary form of two" in various cases, and also "in oral use where it is necessary to be clear that two and not to or too is meant."

Regarding other suggestions: My understanding of the many senses of tierce is that while all of them are related to the number three, none of them would make any sense in a phrase like "*cleave in tierce". Trey means "a playing card with the rank of three" or "a score of three in cards, dice, or dominoes".

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Actually I googled about tierce and trey. They both have meaning of the canonical sum one plus one plus one. –  speedyGonzales Jan 13 '12 at 9:04

George MacDonald Fraser in 'Quartered Safe out here' used a term like this. He was asked to destroy a boat with a bazooka and I think (don't have book anymore) I remember a line "Cleave it in twain, thrain if necessary"

You will have to check.

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I'd go for tern from the Middle English. Derived from the Latin terni and the French terene.

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But that's not a phrase with usage comparable to "cleave in twain". It's nonstandard in any application, whereas "cleave in twain" is recognized as a standard archaism. –  Daniel Jun 17 '14 at 22:50
A source and example usage would go a long way. –  dwjohnston Jun 17 '14 at 23:48
I like this one, although it's very obscure. In some programming languages there is an operator called the "ternary operator", meaning it is an operator with three parts: the conditional statement; the true result; and the false result. Now I know where the word "ternary" comes from. E.g. for C#: bool Go = LightColor == Green ? true : false; –  Cyberherbalist Jun 18 '14 at 0:12

The literal answer is, somewhat boringly, "in three". Tracing the etymology back to Old English when numbers had gender:

ModE two <- ME twa <- OE twa feminine-neuter form of "two"

ModE twain <- ME tweyne/tweien/twaine <- OE twegen, masculine form of twa "two"

but

ModE three <- ME three <- OE þrīe / þrēo, masculine/fem-neuter forms of "three"

But I suppose you are looking for something with a similar "flavor" rather than a strict parallel.

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I'll add one more, to the same pattern: trine.

I'm familiar with it mostly in astrology, where it refers to a separation of 120 degrees; a grand trine consists of three planets, each in a different sign, all with separations of 120∘, forming aan equilateral triangle when linked.

And I think cleave in trine would work nicely.

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This answer sounds quite euphonious! Though I doubt the implication behind "to the same pattern". I'm pretty sure that "trine" is a Romance borrowing, while "twain" is a direct Anglo-saxon descendant. –  Mark Beadles Jan 13 '12 at 21:11
Yeah, the fact that they're both /t/ would tend to support that. On the other hand, that's a good thing for suggesting twain. As you say, it's euphonious, and sound symbolism pays no attention to etymology. –  John Lawler Jan 13 '12 at 22:05

Trifurcate. (a bit too equal?) Trisect. (a bit too accurate?) Tripart. Trichotomize. The OED fizzles out after this.

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I think the questioner was asking for nouns to use in parallel to "twain", like "cleave in (something meaning three)". –  Mark Beadles Jan 13 '12 at 21:12
Quite likely. I read it as that he was looking for a phrase like "cleave in twain". I mustn't jump to conclusions next time... :) –  cormullion Jan 13 '12 at 22:03

You could try the verb third. It's really no different from 'halve', but it has something of the archaic flavour you seem to be looking for.

(It goes back to Shakespeare: Two Noble Kinsmen i. ii. 96 What man Thirds his owne worth.)

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The closest is probably `tierce`. The second-closest is probably `trey`.

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