Viz. is the abbreviated form of the Latin “videlicet”. The “i” in “viz” is pronounced like the “i” in “bit”, “it” and “pit”. The word is normally employed in formal writing and is used to expand on or clarify what has already been said.
Here are a few examples.*The Department offers two modules in Teaching English as a Second Language, viz. Applied Linguistics, and Principles of Language Teaching. *I want to talk about a major threat facing our society, viz. global warming. The word can be replaced by “namely”, and in speech most people tend to say “namely” rather than “viz”.