I Google-searched "dimensional charting" to get more information about this term. Guess what? All the results on page 1 are related to Dc.js. Looks like they'll have to write the definition themselves :-P
With crossfilter.js your data gets structured similarly and then bound to d3.js svg charts. dc.js provides the glue between the two to make it easier to work with. This allows you to interactively select part of a chart and immediately see other charts bound to that data get filtered at the same time.
It allows for an interesting way to explore / visualize data.