Utterer and Witnesser

Utterer noun - Someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous).

Witnesser and utterer are semantically related. In some cases you can replace term "Witnesser" with "Utterer", this nouns are similar.

Witnesser noun - Someone who sees an event and reports what happened.

Utterer and witnesser are semantically related. You can use "Utterer" instead a noun "Witnesser".