Stand naked in the corner of a room with arms extended like the hands of a clock while rocking hips side to side to slap one's balls against his thigh rhythmically with every second

While mooning someone, the mooner bends over exposing his dick and balls. He then sways back and fourth as to make his dick look like the long pendulum on a grandfather clock

When one gets on a table without your pants on, and swing your junk left to right.

A party trick, whereby you fool the victim into looking at your penis stretched around your wrist. Usually done while drunk. Originated in Bloomsburg PA in the mid 1990's

When a male of over 65 years old swings his cock back and forth over a young woman's face until he cums. Which is almost always 12:00.

GrandFather Sauce Meaning: A man of the age 60 or older's diarrhea

When you're trying to shop for some antique grandfather clocks for your paps but then you unfortunately forget the "l" in "grandfather clock" and now you wish you were dead.