Little fastener

NUT

Think of what secures a bolt but isn’t a screw or washer.

"Little fastener" is a straightforward clue where "little" hints at something small, and "fastener" refers to an object that holds things together. The answer is "NUT," a small metal piece that screws onto a bolt to secure it. The wordplay is simple—no tricks here—just a direct definition where "little" emphasizes the size of the nut. It’s a common term in hardware, so most people will recognize it right away.