The goal of the Buddha's doctrine is said to be the eradication of 'dukkha' variously translated as anguish, stress, unsatisfactoriness, pain... what is the definition of this term as given in the suttas? What is the intended scope of this term?
The term is mentioned and described in a large number of suttas.
Generally, dukkha it is divided into three types: dukkha-dukkha, which is what we commonly think of as suffering: pain, aging, stress, unpleasant things, etc.; viparanama-dukkha, which is the suffering of change: this includes not getting what you want, and the fact that satisfaction is always temporary; and sankhara-dukkha, the fact that everything is conditioned (i.e., impermanent and essenceless.)
The etymology of the term dukkha may be helpful here; the image is of a faulty axle alignment. In other words, life is like the supermarket cart with the wonky wheel.
The scope is all-pervasive; it refers to the fact that nothing (outside of nirvana, which is unconditioned) is completely satisfactory.