Question

What is electronegativity ?

Answer 1

Tendency of an element to attract/gain electrons is called electronegativity. Elements which need only few more electrons are electronegative. 
As the number of protons in the nucleus increases, the electronegativity or attraction will increase. Therefore electronegativity increases from left to right in a row in the periodic table.

Answer 2

electronegativity symbol x is a chemical property that describes the tendency of an atom to attract a shared paired of an electron towards itself.