Real Dictionary

increase
countable noun: If there is an increase in the number, level, or amount of something, it becomes greater.
verb: If something increases or you increase it, it becomes greater in number, level, or amount.

increase in American English
an increasing or becoming increased
to become greater in size, amount, degree, etc.; grow
to cause to become greater in size, amount, degree, etc.; add to; augment
intransitive verb: to become greater, as in number, size, strength, or quality
noun: growth or augmentation in numbers, size, strength, quality, etc
transitive verb: to make greater, as in number, size, strength, or quality; augment; add to

increase in British English
noun: the act of increasing; augmentation
verb: to make or become greater in size, degree, frequency, etc; grow or expand