Lankness

The boy's lankness reflected his malnutrition.

Source: wiktionary

The gravity of his dress, together with a certain lankness of cheek and stiffness of deportment, added nearly ten years to his age, but his figure was that of one not yet past thirty.

Source: wiktionary

Phryne going to the Bath as Venus.— […] Was ever such a heap of rag dolls ever brought together and called men and women. Venuses indeed!—say rather limp-lanknesses seen through a burnt-sienna fog in a classical dream after falling asleep over one of Racine’s tragedies.

Source: wiktionary

When he turned inquiringly toward them they saw that he was stoop-shouldered; though not from any deformity, but from sheer, slouching lankness.

Source: wiktionary