knobby

“That’s good,” he said, before pointing a knobby finger at me.

The tree has the look of an ancient thing — knobby and gnarled and thick, so thick and tall it appeared at times like several oaks stacked on top of one another.

Some of these descendants make up what's known as the adaptive immune system: highly specialized B and T lymphocytes that each recognize just one particular three-dimensional structure -- perhaps a pointy bit here or a telltale knobby clump there -- that betrays an invading virus or bacteria.

On a recent drive north of Sacramento, I spotted a row of knobby peaks that looked more like a children’s book illustration than real-life mountains.

The boy is tall and lanky, with knobby knees poking out of his shorts and messy dark brown hair.