Skelatinous 

state of being exceptionally thin; having a body habitus similar to a skeleton; (pronunciation-rhymes with gelatinous)

The old man was skelatinous and looked as though he hadn't had a good meal in years

Skelatinous by HossWrangler September 11, 2019

Skeletinous

Referring to a person or thing that is skeleton-like in physique.

Due to his skeletinous stature, he was unable to participate in full contact sports, without literally disintegrating.

Skeletinous by Sh3WantsTh3D July 17, 2021

Skeletonous 

The opposite of "gluttonous", derived from ones skeletony appearance due to malnutrition, tick tok craze, or miserable fad diet.

"Today, UN peacekeeper operations deployed aid to rural Mississippi, commanders on the ground where agast at the locals skeletonous appearance"

And;

"You seen Becky lately? She used to be thicc now she's skeletonous"

Skeletonous by D@niel Verde January 12, 2022