Ethnic cleansing involves forcible expulsion of a population -- not just mass killing -- with the goal of achieving cultural or racial homogeneity in a given territory.

Israel is guilty of both the forcible expulsion and mass killing of Palestinians, so the definition certainly applies.

The resistance and the resilience of the Palestinian people have prevented their ethnic cleansing. This is not because Israel isn't trying as hard as it can within the bounds the international community is allowing.