Irish twins are "two children born to the same mother within 12 months of each other." Technically my girls missed being irish twins by 2 months (they're 14 months apart). But, I have learned over the years that those two months don't really matter. My girls are very close and affectionate with each other, and have a sibling bond that I don't know if I've ever encountered before. I have often told people it's like living with twins, to the point where they even finish each others sentences. They have been in the same size clothes since the younger one was 6 months old, and ever since they became the same height, I often get asked if they are twins. Most recently, their newest adventure is dressing alike, in hopes that people will actually think they are. Well, yesterday was their newest "we have to do things together" adventure. They lost the same tooth, on the same day. They literally had me pull them out one right after the other. They thought it was the funniest thing ever.
My hope is that someday they will include their "Irish triplet" in their escapades :).