The spelling of "itty" is rather unique and may cause confusion for some. The word is pronounced as /ˈɪti/ which explains the choice of letters used to form the word. The "i" sounds like the "i" in "bit" and the "t" represents the /t/ sound. The double "t" may seem unnecessary, but it serves to emphasize the /t/ sound and distinguish it from similar words like "ity". Despite its unconventional spelling, "itty" is commonly used in casual language to refer to something small or cute.
The term itty is believed to be a diminutive form of the word little or itty-bitty. The exact etymology of itty is unclear and difficult to trace. It is considered to be an informal slang term that originated in American English, particularly in African American Vernacular English (AAVE) and later entered mainstream usage. This colloquial truncation has also spawned similar formations, such as teensy, wee, or itsy-bitsy.