Verbs

(v)multiplycombine by multiplication“multiply 10 by 15”
(v)multiply, manifoldcombine or increase by multiplication“He managed to multiply his profits”
(v)manifold, multiplymake multiple copies of“multiply a letter”
(v)breed, multiplyhave young (animals) or reproduce (organisms)“pandas rarely breed in captivity”
(v)reproduce, procreate, multiplyhave offspring or produce more individuals of a given animal or plant“The Bible tells people to procreate”, “These bacteria reproduce”

Adverbs

(r)multiplyin several ways; in a multiple manner“they were multiply checked for errors”