But it’s not monomorphemic.
Tatamagouchi is both, though, (at least for English speakers) because it’s a place name. The cool thing about place names is that they can get pretty long, without internal morpheme boundaries to mess things up. Long names (four or more syllables) are good for telling us where secondary stress likes to go when there’s no derivational residue. So, perhaps, are active ingredients in heartburn medication.
It might seem ironic that so many such names are in the Americas, far from the island that bequeathed us with this stress pattern. There’s a sizable set of four-or-more-syllable names in the western hemisphere – Alabama, Mississippi, California, Minnesota, Arizona, Massachusetts, Manitoba, Carolina, Guatemala, Argentina, Venezuela, Tallahassee are ones that we probably all know without getting local, like Maniwaki or Petawawa. Similar four-or-more-syllable names are comparatively lacking in England, probably for at least two reasons: first, the pattern of syncopating names, as in Salisbury → [sælzbri] (or [salzbri]?), and second, because of the transparently derived nature of other forms, as in Kingston-upon-Thames or Canterbury. (But researching this has reminded me that Picadilly is 4 syllables, and not transparently derived in any way – if you know others, I’d love to hear about them).
To be fair, internal morphological structure is pretty easy to detect in English toponyms when they are derived with English morphemes. (In contrast, the western-hemisphere examples above are all borrowed, and their morphological complexity has been obscured). So it shouldn’t really be a surprise that you need to leave England to find long place names without obvious internal morphological structure. A case in point is found in the Irish-pub standard tune It’s Long way to Tipperary , which is not quite Irish in origin, but instead dates from WW1-era England. I once read (but it may be a legend) that the English composer (of Irish descent) who wrote it chose “Tipperary” as the “home” in the song because it is one of the few places in the British Isles that has that exact stress pattern (trochee-trochee) to fit in the lyrics (and it just barely rhymes with Picadilly). Mind you a bit of google research offers alternative histories, and it also doesn’t take long to find other 4-or-more-syllable names in Ireland, like Carrickfergus, Enniscorthy, and Ballymakenny. Although, whether you consider these not to have any internal morphological structure is an additional issue that may expose your politics.
Five-syllable names like Tàtamagóuchi add to the picture: the dactyl-trochee combo in such cases is evidence that English likes to put primary stress on a final trochee and secondary stress on an initial left-headed foot, even if adjacent syllables end up unstressed in the middle of the word. (I should add that you can call it a trochee followed by an unfooted syllable, as in (Tàta)ma(góuchi), or a dactyl-trochee sequence, as in (Tàtama)(góuchi) ). Dactyl-trochee forms are rare enough that you might believe them to be lexical exceptions, but their rarity follows from (among other things) the rarity of pentasyllabic forms (other examples include Winnepesaukee and perhaps Winnipegosis).
But then if you go back to four-syllable names that, for whatever reason, require final primary stress, the attraction of the initial syllable for secondary stress persists. Some examples include Kàlamazóo (a town in Michigan), Ànapamú (a Santa Barbara name of Chumash origin), and Àntigonísh (a town in Nova Scotia). In the first two cases, the final [u] attracts stress (compare the final unstressed vowels of the above examples Alabama through Petawawa and Picadilly through Carrickfergus). In the third case, names in -onish always have final stress. These are all dactyl-trochees too, except that the trochee is a heavy monosyllable.
So what does this have to do with heartburn? Yesterday I overheard a comparison of the active ingredients of three medications:
OK, this one has cimetidine, this one has ramitidine, and this one has famotidine.
The relevant parts are [sɪ̀mətədín], [ræ̀mətədín], and [fæ̀mətədín], not that the exact vowel quality of the stressed vowels (or the lack of flapping) is that important, but the stress placement is. These are obscure terms whose stress pattern is probably not stored as an exemplar in your head, and whose internal morphology is either missing or tenuously retrievable from the cran morph -dine. For some reason, stress is attracted to the final syllable, but more striking is that the secondary stress ended up on the initial syllable, just like in Kalamazoo. What gives? It might just be that stress showed up on the intitial syllable to enhance contrast, which weakens the case for saying that’s where it wants to be anyway, but it just didn’t seem difficult for it to go there.