lanky
Tall and very thin in a slightly awkward way.
Lanky describes someone who is tall and thin in an awkward or ungraceful way, with long arms and long legs that seem a bit too long for their body. A lanky basketball player might have knees and elbows that stick out at odd angles, making them look like they haven't quite grown into their height yet.
The word captures that gangly quality you often see in teenagers going through growth spurts, when their limbs seem to grow faster than the rest of them. A lanky person might move in a slightly clumsy way, with their long legs taking big strides and their long arms swinging at their sides.
Many lanky kids eventually grow into their frames and become graceful athletes or dancers. Even though lanky can suggest awkwardness, it isn't meant as an insult. It's just an honest description of a particular body type, often temporary, that can come with being tall and thin before your coordination catches up with your height.