Other forms: scraggliest
Use the adjective scraggly for anything that's messy, uneven, or sparse — like your teenage cousin's scraggly beard.
In England, scraggly (or, alternatively, scraggy) is primarily used to describe a skinny person or animal. North Americans are more likely to talk about the dry, scraggly brush in the desert or their scraggly hair first thing in the morning when they roll out of bed. Related adjectives that are now obsolete included scraggling and scragged, all from a Scandinavian root.