Scrawniness is a word used to describe a thinness or lack of body mass. Synonyms for scrawniness include skinny, thin, gaunt, bony, emaciated, frail, and undernourished. Skinny refers to a generally slim figure, while thin implies a lack of body mass. Gaunt and bony describe a thinness that highlights prominent bones and a hollow appearance. Emaciated and frail emphasize a thinness that is the result of poor health or malnourishment, with emaciated also having a connotation of overall weakness. Undernourished implies that a lack of proper nutrition is the cause of the thinness. All of these synonyms reflect the same basic concept of scrawniness, with varying nuances of connotation.