um

1. An expression used to show contentment for something

   Mmm, this is a tasty pie!

2. An expression used to show thought or reflection

   Mmm, I see what you mean.

3. An expression used to show being muffled or not able to speak clearly, as well as "mmph".
4. Yes.

verb

To make the um sound to express uncertainty or hesitancy.

1. Expression of hesitation, uncertainty or space filler in conversation. See uh.

   Let’s see... um... how about this?

preposition

Around, about; after.

noun

Alternative spelling of µm