Define electronegativity. How does it differ from electron gain enthalpy?

(N/A) Electronegativity is defined as the tendency of an atom in a chemical compound to attract a shared pair of electrons towards itself.
Differences between electronegativity and electron gain enthalpy:
$1$. Electronegativity is a relative tendency of an atom to attract electrons in a bonded state,whereas electron gain enthalpy is the energy change when an electron is added to an isolated gaseous atom.
$2$. Electronegativity is not a measurable quantity,while electron gain enthalpy can be measured experimentally.
$3$. Electronegativity is not a constant value for an element as it depends on the bonded atom,whereas electron gain enthalpy is a characteristic property of an element.