Caryn, I'd fix the label, as these all too easily end up falling off with handling.
Do you have a good, general-purpose sewing book with a substantive section on fabrics? I highly recommend getting an older "McCall's Sewing Book" (I have the 1968 edition). It has an excellent, basic but thorough section on fabrics--discussing the difference between fiber and weave, naturals and synthetics, and types of fabrics. It also has great info on sleeve and neckline styles, collar types, pocket types, etc. It will answer many questions about terms, fabric, etc. I have several sewing books, but that one's my first "go-to" one, especially when trying to determine a fabric.
To your specific question, lame' is generally used to specify yard-goods material, and a lame dress would be one that is all metallic. Your dress looks like it's shot through with Lurex yarn/threads, which was a popular treatment, but it's hard to tell because of the reflectivity of the fabric and how it presents in photos.... If it is a "normal" fabric but intermittently threaded with Lurex, it's not really a lame'. If the entire fabric is woven/knitted with all metallic yarns, then I'd call it lame'.