Words at Play : Words For Things You Didn't Know Have Names, Vol. 2
Definition:
a movable pin in a buckle that passes through a hole in the strap to be secured
Example Sentence:
He knew he'd put on weight when the buckle's tongue found comfort in a hole
closer to the tip of his belt.
About the Word:
The object got its name from its resemblance to an animal tongue elongated
and fastened at one end only.