If you’ve ever heard a young child stammer and trip over his words, you know what it means to stutter.
Use the verb stutter when someone gets stuck on certain word sounds, either because she’s speaking too quickly or eagerly, or because she has an actual speech disorder, also called a stutter. The word itself is somewhat onomatopoeic — a word that sounds like what it means — with its repeated t sounds. Stutter is thought to be related to the Middle Low German word stoten, “to knock or strike against,” which is the way a stutterer’s words sometimes sound.
Everyone’s making jokes but if you’re serious they meant “stuttering”.
Edit: per vocabulary.com