A filled pause is a non-silent pause in an otherwise fluent speech, where instead of a silent pause there is a filler. The filler can be non-lexical or semiarticulate utterances such as huh, uh, erm, um, or hmm. Fillers may also include words such as well, so, I mean, and like, when used in ways that don't change the meaning of the surrounding speech. [1]
This particular type of pause is one of several types of speech disfluencies, which also includes silent pauses, "false starts", phrases that are restarted or repeated, and repeated syllables.