Ross
English is only my second language.....
It is an enclosure to grow orchid in and by the language rules I have learned in school you can create the word orchidarium.
But I found the company you probably refering to......... This is as if a company protects "orchid pot" which would be ridiculous.
I grow orchids , not selling cabinets, as non commercial grower I use orchidarium until they ask me not to.
IF a protected brand has been so common that it defines all similar product the protection is lost, at least in Europe. Therefore there is no possibility to protect ordinary, obvius words as brand names.
If the company ask me to stop using "orchidarium" i will consider doing so!