How do I spell the truncation 'Cas', as in 'Sports Casual/Sports Cas'? It may be UK only, and may have been spawned by Alan Partridge. Cash/Cas are not right.
*As in a slang term, "he was acting all cas".
This slang contraction appears to be too new for most dictionaries or Google NGrams. Since it's slang and new, I took at look at social networking and the web for ideas. More commonly used forms often lead to standard forms over time, all else being equal.
Google Searches reveal that "cas dress" (6,000+ hits for me) is found much more often than "cazh dress" (50+ hits for me). "dress cas" is actually quite common, with 130,000+ hits for me compared to only 60 for "dress cazh".
Twitter Search shows that cazh is used, mostly by people asking how to abbreviate 'casual'. A cas search has far too many unrelated results to judge. "cas dress" has only 4 hits and "dress cas" only 1 applicable, but "cazh dress/dress cazh" and "cash dress/dress cash" have no related results.
I also did Twitter and Facebook searches for "sports cas" and "sports cazh" but there were no related results in either case.
Based on social networking results, I'd say that there is still no common way to spell this abbreviation - but if pressed, 'cas' seems to be slightly more common than 'cazh'. It seems that more people simply abbreviate the existing word "casual" than try for a slightly obscure phonetic spelling.
I take it that what you want is how to spell a word that is understood when spoken but which is not (yet) in a dictionary with a generally recognized/recognizable spelling — that is, a spelling for the shortening of casual to the first syllable, which in IPA is /kæʒ/.
First, the bad news. There is no accepted consistent spelling for such a sound in standard written English. The sound isn’t terribly rare, found in measure, leisure, casual, Asian. These all involve the letter s and a vowel, which would look alien at the end of a word. If you write it as cas, cash, or caj, those spellings are already so specifically pronounced with /s/, /ʃ/, or /dj/ respectively (unvoiced fricatives or voiced affricate), that one would be hard pressed to imagine that the spelling is intended to be a voiced fricative.
Then the slightly-not-so-bad news. Even though there is no accepted spelling for this sound at the end of a word, one can still use zh. It is not a standard spelling of anything in English, and because of that would be expected to be pronounced as something other than s or sh. Also, it does not require a following vowel which would be much more alien.
So I suggest that if you must write this word, that it be written as
Though slightly strange looking, it is less so than IPA, and is more likely to be pronounced as you want, at least compared with the cas or cash spellings, which probably would not be pronounced the way you want.
I appreciate the answers here which seek a grammatically logical way to spell the word. From an aesthetic point of view, however, cazh does not strike me as the best route. I think it destroys the casual tone sought by the author.
Examine other similar spoken truncations in colloquial speech:
We see the trend established in this type of slang to use letters and sounds common to the truncated word. There is a literal truncation at three letters; it is a spoken abbreviation. From a reader's perspective, "bro" is easily scanned and parsed as the expanded "brother".
There are a few exceptions of course, such as cuz for because. The truncation bec doesn't involve the stressed portion of the word and fails to impart the intended meaning, so an alternative is sought. A new letter is brought in, but again this is easily parsed and pronounced with the same phonetic sounds found in the root word. I've seen several variations of this one, all phonetically equivalent. Sitch for situation brings in a new letter both to distinguish it from the English word sit and to retain the /ʧ/ sound. As with cuz, the word is easily parsed by the reader.
In keeping with that trend, the natural abbreviation for casual is cas. We aren't tripping on any other English word, and the stressed portion is contained in the truncated form. Within the framework established by other common spoken truncations, the reasons to bring in new letters don't exist here. Moreover, zh is not familiar to most English speakers. It winds up as a white elephant in that it is not quickly parsed, the eye pauses on the unfamiliar combination of letters. The reader must then decipher the meaning, and thus the casual tone is lost--you may as well have used a completely unfamiliar term or a formal tone.
I think you're better served using cas or, if you must, cas'.
As a slang term I don't think there is a "standard" spelling (OED, NOAD) of the abbreviation of "casual" to "cazh". What I just wrote is probably most evocative of the American pronunciation of such a word, but "casual" is not spelled with a zh. "Cas" or "Caz" would probably be fine as long as your audience understands the slang.
I think this is one of those things where it may be hip to say cazh. But the risk of misunderstanding in writing combine with the written word being less ungainly than the spoken with casual. So I would write out casual if it was an explanation.
If it is a fictional quote or marketing material I may coin my own spelling like kaj or cazh. If it's a real quote maybe cäs.