There are lots of words that mean "to comprehend" (and questions asking about such words), but it's hard to find examples that make the connotation of such words clear.
What words have a connotation (or explicit definition, I suppose) that implies a level of understanding, eg. a shallow understanding, an intuitive understanding, a deep understanding of all aspects of the issue, etc.
The example that comes to mind is "grok", which was coined by Heinlein in Stranger in a Strange Land and means "to understand fully". Are there other words (preferably that are relatively widely used; grok counts, but most authors aren't fortunate enough to coin a word that will be used outside of their work) that mean a specific level of understanding?
Example words that come to mind, but for which I don't have a good idea of what level of understanding they imply (if any) include: