I'd like to offer some additional amateur translation options for "homoiconic" to Latin. There's already a decent word "conformis" which has the close English counterpart "conformal", but if we're inventing new words, I'd propose "coninstar", as in "con-" meaning "together in/sharing" and "instar" being "representation/form".
Con- before vowels is co-; compare cohabit; coincide.
(Technically, you wouldn't expect an N before vowels anyway because the root word ends in an M, so hypothetically you'd have "cominstar". But since the consonant just disappears before vowels, that's moot. [Though technically technically, disappearing when before vowels is expected of M - this is a feature of Latin pronunciation generally - and not of N.])
I'll plead ignorance here, and ask for clemency on the grounds that modern coinages like "conurbation" may be exempt, and also that there seem to be notable exceptions to this rule, like this example I've thrown together[0] :
"con"+"iacio" (also "jacio")
=> "conicio" (also "coicio" also "conjicio")
(Also "coinstar" is a trademark of those spare change gobblers you find after the register at Walmart.)
It'd be a better example of an exception if it unambiguously started with a vowel. This is sort of the reverse of the case I pointed to above, where "habito" does start with a vowel, or rather it almost does, enough to trigger the same changes.
> Before vowels and aspirates, it is reduced to co-; before -g-, it is assimilated to cog- or con-; before -l-, assimilated to col-; before -r-, assimilated to cor-; before -c-, -d-, -j-, -n-, -q-, -s-, -t-, and -v-, it is assimilated to con-, which was so frequent that it often was used as the normal form.
I and J aren't different letters in Latin, but they are different kinds of sound, if sometimes only hazily different. Same goes for U and V. By modern convention we have convention and conjecture; the hazy difference seems sufficient to explain why the Romans left us every variety of the compound, from coniicio through conicio to coicio. A naive analysis (the most I can really do) would say that coniicio comes from someone who sees iacio as starting with a consonant, coicio comes from someone who doesn't, and conicio is a reduced form of coniicio.
That's not the most objective decision in the world. If we're describing "conurbation" in specific, why not call -urb- English too, taken from the common English word urban? Urban ultimately draws from Latin urbs, but so does con- draw from com- and -ation draw from -io(n).
(In Latin, there are plenty of words ending in -atio(n); however, within the language this is not a single unit, it's a sequence of part of the verb stem plus two separate morphemes -a-t-io(n). The -at- marks the passive participial form of an a-stem verb; compare faction (zero-stem), inhibition (e-stem).)
