The quality of being advisable; the state of being recommended or sensible as a course of action.
From advisable plus the noun-forming suffix -ness (expressing a quality or state). This is a more direct formation than 'advisability,' using the older Germanic suffix pattern rather than the Romance-derived -ity.
English has two ways to make similar meanings: 'advisability' (Latinate) and 'advisableness' (Germanic), showing how our language is a hybrid that lets us express the same idea with different word roots.
Complete word intelligence in one call. Free tier — 50 lookups/day.