Carbohydrates are classified in three major categories depending upon the number of sub units joining to form them. These are,
Monosaccharides
Oligosaccharides
Polysachharides
The simplest single units are monosaccharides, if units are ranging between two and twenty they are called oligosaccharides and above twenty joining units they are called polysachharides.
Result:
The proper name for a carbohydrate polymer with 2 subunits is called Oligosachharide in general and Disaccharide in specific.