Dukkha is often translated as suffering, but it is wider: the pain of birth, ageing, sickness and death, the stress of change, and the subtle unsatisfactoriness of all conditioned things. It is the first of the four noble truths and one of the three marks of existence.
Dukkha
Suffering, unsatisfactoriness: the first noble truth, that conditioned existence cannot finally satisfy.
Also: Duhkha, suffering