Integral means essential or necessary for completeness.
Integral is an adjective.
Synonyms: basic, requisite, necessary, constituent, essential, indispensable.
Antonyms: unnecessary, unimportant, peripheral, unessential.
Note: Integral can also mean whole or complete.
It was a class of integral calculus.
Hyderabad is an integral part of Andhra Pradesh.
Our workers are an integral part of the company. We must find some other way to cut costs.
Mr.Ravi is an integral part of our success; we could not succeed without his talent.