Answer:
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).
ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢꨄ︎Goodnight
