[rvense]

The problem with "word", as with many terms in linguistics, is that it's a prescientific unit of analysis.

I certainly think most linguistic typologists would say that there is no cross-linguistic unit that corresponds to our intuitive understanding of word, which is really grounded mostly in orthography.

And I think it's fairly easy to show that orthography should not have much say in this matter, though. Of course you can't get around it in language didactics, but in scientific description we need to be very careful with it. Bob Dixon and Alexandra Aikhenvald give some examples from Bantu languages in their Word: A cross-linguistic typology. In Sotho, the sentence "We will skin it with his knife" is written "Re tlo e bua ka thipa ya gagwe", while in the orthographies for Zulu and Xhosa, the same sentence would be rendered as "Retloebua kathipa yagagwe". You really need to look at each language to find a sensible set of analytical categories, and be very explicit about your criteria, be they syntactic, semantic or phonological.

[Mezzie]

Linguistics has the distinction for what you're talking about: Morpheme versus word. Morphology is the study of this area. I freaking loved my Morphology classes.

[rvense]

While I think there's a generally accepted definition of morpheme (as the smallest distinctive unit), that doesn't give you a good definition of the word. (Because there isn't one.)

Funny you use the term morphology like that. To me it's basically synonymous with inflection, very traditional, where morpheme is very much a structuralist term. But all my teachers were cognitive-functional linguists, so everything was cut rather different and sometimes it's hard to talk.

[Mezzie]

Yeah, my morphology teacher was a structuralist, and this was quite a while ago, so I have no doubt I'm biased there. (I actually preferred the cognitive stuff I was introduced to; I really liked working with metaphor in their systems and syntax/phonology/morphology were less my thing than semantics and sociolinguistics.)

You're definitely right that the definitions aren't cut-and-dried and that makes typology rather difficult.