Does ionisation energy depend on electronegativity?

[LogicalAcid]

Because, if a higher electronegativity means a higher attraction to electrons an atom has, wouldn't that mean that a greater energy would have to be put in to ionise an atom with a higher electronegativity?

[cgk]

Its rather the other way around: Electronegativity depends on the ionization potential. In fact, one popular definition of eletronegativity is
EN = (1/2) * (EA + IP)
where EA is the electron affinity and IP is the ionization potential.

The concept of electronegativity is more qualitative than that of an ionization potential or an electron affinity. The latter two quantities have clear definitions in terms of actual measurements, and can be calculated or determined experimentally. Electronegativity, on the other hand, is a more general qualitative concept introduced to make sense of chemical reactions; it cannot be measured directly.