Question

what is defined as verb?

Answer 1

a word used to describe an action, 

Answer 2

$\huge{Answer}$

A verb is a word or group of words which says what a person or a thing is, has or does, or what happens or is done to a person or a thing.

For examples :

Ravi plays.

Ravi is playing .

Ravi has been playing.

Ravi shall have been playing.

Here we see that the verb often consists of more then one word, even up to four words - plays; is playing; has been playing; shall have been playing.