- Z1 [zɛd, US zi:](also z)noun (plural Zs or Z's)1》 the twenty-sixth letter of the alphabet.2》 denoting the next after Y in a set of items, categories, etc.3》 (usu. z) the third unknown quantity in an algebraic expression.↘denoting the third axis in a three-dimensional system of coordinates.4》 used in repeated form to represent buzzing or snoring.Phrasescatch some (or a few) Zs N. Amer. informal get some sleep.————————Z2abbreviation Zambia (international vehicle registration).symbol Chemistry atomic number.
English new terms dictionary. 2014.