The word "stintier" is spelled with a double i in the middle because it comes from the verb "to stint" which means to limit or restrict something. In IPA phonetic transcription, it is pronounced /ˈstɪntiər/ with a short i sound followed by an unstressed schwa sound and ending with the r sound. It can be used to describe someone who is more restrictive or frugal than others. For example, "She's very stintier than her sister with her money."