Also see "clam"
Question:
Do people actually sign "clam soup" to mean clam chowder?
Answer:
If the person doing the signing is "bilingual" and/or does the shopping (and therefore sees the can of soup with the word "chowder" on it) that person will likely know that this type of "soup" is officially called "clam chowder."
Honestly? The wife (Bee) and I just spell "clam chowder" when conversing with each other. Once in a while we might sign "clam soup" but those of us who are Deaf can usually spell "clam" faster than most folks can do a two-handed awkward clam-shell
open/close/open movement. Then we just do cursive (finger mumbled) version of "chowder" that hits the CH mumbles the middle and hits a strong R at the end.
If you think about it though, clam chowder really is just thick clam soup.
As far as New England style clam chowder versus Manhattan style clam chowder vs -- there is just no way we are spelling that out. In real life it tends to be:
1. clam soup white
or
2. clam soup red
Some folks of course "do" just spell out "C-L-A-M C-H-O-W-D-E-R" and add red or white only if there are both options provided -- otherwise it defaults to white (at least out here on the west coast).
Oh sure, you will get some folks who get all concerned about it and who actually know how to spell Manhattan (without spell-check) but those folks probably live in or near Manhattan.
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See: SOUP
See: THIN
See: THICK