Pertaining to belief. Alternatively, also pertaining to states sufficiently like beliefs (thoughts, judgments, opinions, desires, wishes, fears).

Often the distinction between doxastic and sub-doxastic states is a way of cashing out the distinction between personal and sub-personal states where instances of the latter include information bearing states not available to awareness (like the information processing going on in the cerebellum). Examples of non-doxastic contentful states would be the numbers of rings in a tree's cross-section: they carry information about the age of the tree, but are neither beliefs (doxastic states), nor states of an entity that has beliefs (sub-doxastic states).
Pete Mandik