Why Are The Dots on Dominoes Called Pips?
The word "pip" commonly means a "spot" or a "speck", and perhaps that's why a domino's spots are called "pips".
"Pip" has been used not only to denote the dots on dominoes, but also the dots on dice, as well as the marks on playing cards (e.g. a four of spades has four spade pips on the card, and is also sometimes called a four-spot).
The small, hard seeds of some fruit, such as those in an apple, orange, or lemon are also called "pips".
Of course, "Pip" was also the name of a character in Charles Dicken's "Great Expectations", though the name didn't have anything to do with dominoes, but instead was a shortening of the character's full name, Philip Pirrip.
Within the context of the game of dominoes, the word "pip" refers to the dots on either end of a domino tile. A domino represents the roll of two dice, and is rectangular with a line down the center. Each end of the tile contains a number, represented by an arrangement of pips. In the most popular domino set, the double-six, the numbers vary from 0 (or blank) to 6, producing 28 unique tiles. In larger domino sets, the numbers can range up to 9, 12, 15, or 18 pips per end. A pip is also referred to as a "dot" or a "spot".