Synonyms: witness, witnesser, informant
Definition: someone who sees an event and reports what happened
Similar words: perceiver, percipient, observer, beholder
Definition: a person who becomes aware (of things or events) through the senses
Similar words: speaker, talker, verbaliser, verbalizer, utterer
Definition: someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)
Usage: the speaker at commencement; an utterer of useful maxims