Those specific types of words are called speech disfluencies, but that is not a verb used to describe what one is doing when they use those words.
This is a bit of a nebulous question since speech disfluencies are used in so many common situations that among some populations they can represent up to 20% of the total words used in everyday conversation.
Verbs used to describe what you are doing when using a disfluency could include :
- If you do not know what to say, and you are indicating to your audience that you are taking a moment to think about it, you may be pondering, considering, or contemplating.
- If you do not know what to say, and the silence is making you uncomfortable, you are fillering.
- If you do not know what to say, and you you are trying to buy time, you are delaying.
- If you know about what you are trying to say, but you have a neurogenic speech impediment that makes saying it difficult, it is ayou are stutterstuttering or stammerstammering. (Some cases of filtering may also be described this way)
- Stutters are often caused by duress; so, if it is caused by a stressful situation you may be faltering or cowering
- If you know what you want to say, but are unsure if you should say it, you are hesitating
- If you know what you want to say, but purposefully include the disfluency for dramatic effect, you may be emphasizing.
- If you are parroting another person's disfluencies you may be mirroring or mocking