Question

can any body give authentic defination of a poles and zeroes of a system in control system

Answer 1

I didn't know how to define them without confusing you so I found clearer definitions.
You may want to reference the site for examples and further clarification.

DEFINITION 1: zeros
1. The value(s) for z where the numerator of the transfer function equals zero
2. The complex frequencies that make the overall gain of the filter transfer function zero.

DEFINITION 2: poles
1. The value(s) for z where the denominator of the transfer function equals zero
2. The complex frequencies that make the overall gain of the filter transfer function infinite.

Source: http://cnx.org/content/m10112/latest/

Answer 2

this is the actual definition of it ,,