Itty-BITTY is an informal term used to describe something that is very small or tiny. It is often used to describe a person or object that is so small it can fit in the palm of your hand. The term 'itty-BITTY' is derived from the combination of two words, 'itty' and 'BITTY, ' which both mean small. The term has been around since the early 1900s and is still used today to describe something that is extremely small.