/ˈɪntɪɡrəl/
being an essential part of sth 必需的；不可或缺的
Music is an integral part of the school’s curriculum.
音乐是这所学校的课程中基本的一环。
~ to sth
Practical experience is integral to the course.
实践经验是这门课程不可缺少的部分。
noun
Mathematics: a function of which a given function is the derivative, i.e. which yields that function when differentiated, and which may express the area under the curve of a graph of the function【数】积分。参见DEFINITE INTEGRAL, INDEFINITE INTEGRAL.