y

noun
  1. The 25th letter of the English alphabet, used in writing and speaking. noun
    The word 'yellow' starts with the letter y.
    In the alphabet, y comes after x and before z.
  2. A variable or unknown quantity in mathematics, often used to represent a dependent variable in equations and functions. noun
    In the equation y = 2x + 3, y is the dependent variable.
    The graph of the function shows how y changes with different values of x.
  3. An abbreviation for 'year' or 'years', commonly used in informal contexts. noun
    The event happened 5 y ago.
    He has been working there for 10 y.
  4. Used to denote the y-axis in a coordinate system, which is the vertical axis in a two-dimensional graph. noun
    The y-axis represents the range of values for the dependent variable.
    On a graph, the y-coordinate indicates how far up or down a point is from the x-axis.