doblar
to fold
double
to make twice as much or as many
+
-ar
verb suffix
Doblar means to fold and can be thought of as double0 + -ar1, because when you fold something, you're essentially doubling it over0.
verb
  1. to fold
    To bend or fold something
    Dobla el papel por la mitad. // Fold the paper in half.
  2. to double
    To double or multiply by two
    El negocio dobló sus ganancias este año. // The business doubled its profits this year.