Common term for "roughly-grind Semolina" (as used to make couscous)
The question seems to confuse some terminology.  Let's first clear some things up.


Bulgur is NOT a grind size.  It is a process.  "Bulgur wheat" (in English anyway) refers to whole or cracked or crushed wheat berries that are parboiled and then dried.  There are various sizes of bulgur sometimes available (e.g., coarse, medium, fine, etc., or sometimes numbers for different sizes).
Couscous is a pasta, not a flour grain size.  Couscous is typically made from semolina flour that is shaped into small pieces of pasta.  If the question is what size flour grind is used to make couscous, then the answer is typically a semolina-size grind.


Okay, now that that's clear, let's address the other issue in the question about size of grind for wheat flour.


Raw whole wheat berries are the largest pieces of wheat and are simply called wheat berries in English.  They refer to the raw, unmilled berries with bran and germ intact, only with the (inedible) husk removed.  They can sometimes be referred to as groats too, though that word is often reserved in English for whole oats.  But technically it means any whole, unmilled grain, including wheat berries.
The next stage down in English is referred to as cracked wheat (or sometimes cracked wheat berries).  This involves either cutting or crushing the wheat berries, but leaving large particles (which I suppose could be the size of bulgur or couscous).  Cracked wheat is sometimes labeled coarse, medium, or fine, etc. or sometimes with numbers to indicate the size.  Sometimes these can be referred to as cut groats too (sometimes also indicated with coarse, fine, etc.), though I don't know that name is commonly used with wheat.


It's important to note that names of the finer grinds of wheat beyond "fine cracked wheat" are dependent on the type of wheat and the extraction level (i.e., whether the bran and germ remain in the flour or not).  While semolina typically refers to a somewhat coarsely ground flour (usually made specifically with durum wheat), it does not typically contain the bran and germ that wheat berries and cracked wheat retain.  If you want a coarsely ground flour that contains the same ingredients as whole wheat berries, you might need to search for a coarsely ground wholemeal or whole-wheat or graham flour (each of which has somewhat different connotations in terms of how it is processed, the extraction rate, etc.).

Once we're in the range of normal flours (and out of the cracked wheat size), the names vary for different grind sizes and are pretty inconsistent.  For example, one flour company may use the term stone ground to specifically indicate a coarser grind, but another company may use the term differently.  Some mills allow a wider range of particle size for a given flour, but others may have a more narrow specification.