lanky

This word carries a specific visual quality of awkwardness. It describes a physique where the limbs seem too long for the person to control comfortably, often evoking an image of stumbling or slouching. While "slender" or "slim" are generally complimentary and imply grace or fitness, "lanky" suggests a lack of coordination. It is most often used to describe teenagers or people who have not yet grown into their height.