How is frailty defined? What does it mean to be fit, intermediate-fit, frail?

How is frailty defined? What does it mean to be fit, intermediate-fit, frail?
BETA - What is the difference between seeing a specialist versus a general oncologist?
BETA - How is smoldering multiple myeloma (SMM) stratified?
(Guest Lecture): Budgeting Workshop Paying for the Costs of Cancer
(Guest Lecture): Studying The Relationship between Myeloma Progression and Diet
(Guest Lecture ): Know Your Myeloma Therapy: Carfilzomib (Kyprolis) with Dr. Harsh Parmar