IPA: //ədˈvaɪzəblnəs//
KK: /ədˈvaɪzəblnəs/
The quality of being recommended or suggested as a good idea.
The advisableness of the decision was debated among the committee members.
Advisableness is formed from "advise" (from Old French *aviser*, meaning to consider or reflect) and the suffix "-able" (meaning capable of) combined with "-ness" (meaning the state of being). The word refers to the state of being capable of being advised or the quality of being advisable.
Think of the word 'advise' which means to consider or reflect, and remember that 'advisableness' refers to the quality of being able to be advised.