Fine brunoise (pronounced "broon-wahz") is a basic culinary arts knife cut which is essentially a tiny cube measuring 1/16 inch × 1/16 inch × 1/16 inch. It's produced by first creating a fine julienne and then cutting it into cubes.
For pictures of the basic knife cuts, see this Knife Cuts Photo Gallery.
You can read more about each of the basic knife cuts via the links below:
And for more about knife cuts, visit the Main Knife Cuts Page.