Is it a coincidence that words ending in -ooch in English tend to be colloquial? If not, why?

Question

There are several words in common English usage that end in -ooch:

• brooch
• cooch
• gooch (these two refer to body parts)
• hooch (alternatively written "hootch")
• klooch
• looch
• mooch
• pooch
• scooch
• scrooch
• smooch

With the exception of "brooch", most seem to be colloquial - several are, in addition, vulgar to some degree. Does this indicate that "-ooch" is a phonetic marker for colloquy in English? If so, that raises all sorts of other questions:

• Are there other such markers for this and other linguistic aspects?

• What would have led to this association?

• Are there other, similar markers in other languages?

Answer 1

Because of the way different sounds developed in English and in languages that English got words from, the sequence "ooch" tends not to regularly arise in words with the most common kinds of origins.

However, that doesn't prevent "ooch" from occurring in words that are onomatopoeic (in a broad sense) or sound symbolic. I think sound symbolic words tend to be perceived as more colloquial than words with other origins, so if "ooch" words have a higher percentage of onomatopeia than other words, that might explain why they are more colloquial on average.

Why "ooch" rarely developed in the most common sources of English vocabulary

In native English words, the “(t)ch” sound arose from palatalization of an earlier /k/ sound. A palatalizing environment would usually also include or affect the previous vowel; for example, the vowel in beech is the result of palatalization (also called I-mutation or umlaut) of the same Proto-Germanic vowel that developed to oo in other contexts.

In words of French origin, an o sound before ch usually developed to “oa” (as in coach, approach, broach) while an /u/ sound (spelled “ou”) usually developed to the diphthong /aʊ/ (still spelled “ou”) as in pouch, couch, vouch (or occasionally instead to u as in scutch from Old French escouche). “Brooch” is a spelling variant of “broach” that was originally pronounced the same way.

In words of Latin or Greek origin, ch pronounced /tʃ/ does not regularly occur (there are a few words like conch where it has come to be used as a spelling pronunciation).

Some of your specific examples

• brooch: as mentioned in the previous section and in user6726's answer, this word has an exceptionally archaic spelling and would regularly be spelled the same as "broach"
• cooch: unclear
• gooch: unclear, I think (I can't find an etymology given for it)
• hooch: according to the Oxford English Dictionary, from "hoochinoo", from Tlingit Hutsnuwu
• mooch: possibly from a somewhat irregular or dialectal alteration of French Anglo-Norman "muscher" according to the OED
• pooch: unclear
• scooch: unclear, possibly influenced by scoot
• scrooch: possibly one variant of a number of related onomatopoeic forms
• smooch: fairly unclear, possibly onomatopoeic or a dialectal variant of an onomatopoeic word

Answer 2

A number of those words are borrowed from other languages, for example kloo(t)ch is Chinook Jargon and the original source seems to be Nootka. "Brooch" is a variant of "broach" pronounced with [o] not [u], and while I pronounce "brooch" with [o], I know others in the same dialect zone pronounce it with [u]. I think this is a spelling pronunciation -- "ooch" is [utʃ], "oach" is [otʃ]. In the case of "mooch", the apparent French source has [u] and it was earlier spelled with u, and in this case spelling adapts to fit pronunciation.

Since [tʃ] in Germanic words comes from **k{i,j} but Umlaut would front earlier oCi to eki, [utʃ] would come from other sources and would not be as common a phoneme sequence. Most of the words seem to be borrowings. Generally speaking, words from Native American languages (also including "hooch") are not in the formal register. A significant number of them just seem to be made up, perhaps because [utʃ] = "ooch" is an under-utilized sequence. Urbandictionary contains a lot of made-up words that have under-utilized phoneme sequences. I would not say that "ooch" is per se a marker of anything, but the existence of a gap makes it possible to informally fill that gap, by applying a strategy "informal made-up words should be somewhat atypical-sounding".