It means someone who's incredibly underweight/thin, to the point where their body looks like nothing but bones in a bag (of skin), so to speak.

it means a person or animal that is extremely thin. cowboy...

it means " a skinny, malnourished person " Or when we use it as a noun it's " an extremely skinny person ". For example : If someone is a bag of bones, they are very underweight . I hope this is which you're looking for :)

it is also a horror fiction by Stephen King.

i think it means very thin if u look at him or her he is like a seklton (haykl admi) or when someone loses weight and becomes very thin and skinny يعني معظم كله عظم like me iam very thin 21 years old and 41 kilo !! Idiom Definitions for 'Bag of bones' If someone is a bag of bones, they are very underweight