Viz. (also rendered viz without a period) and videlicet are adverbs used as synonyms of “namely, that is to say, as follows.”
Viz. is an abbreviation of videlicet, which is Latin for “it is permitted to see.” Both forms introduce a specification or description of something stated earlier; this is often a list preceded by a colon (:). Although both forms survive in English, viz. is far more common than videlicet.
A similar expression is scilicet, abbreviated as sc., which is Latin for “it is permitted to know.” Viz. is usually used to elaborate or detail text which precedes it, while sc. provides a parenthetic clarification, removes an ambiguity, or supplies a word omitted in preceding text.
Viz. is usually read as “namely” or “to wit,” but is sometimes pronounced as /viz/.
Videlicet is pronounced /vəˈdeləˌset/.
Scilicet can be read as “namely” or “to wit” or pronounced as /ˈsiləˌset/.
Viz. is the medieval scribal abbreviation for videlicet. It is the letters v and i followed by the common medieval Latin contraction for et and -et, which was a glyph similar to the numeral 3 or the Middle English letter yogh (approximately ʒ) although it was not related to either.
Videlicet is a contraction of Classical Latin vidēre licet, which meant “it may be seen, evidently, clearly” (vidēre, to see; licet, third person singular present tense of licēre, to be permitted). In Latin, videlicet was used to confirm a previous sentence or to state its contrary.