@Jebediah,
Yes, mainly. But I am sure it is also true that the more general words are harder to define. There are words we think we know the meaning of, until we try and explain it, and then find that it is really very hard to pin down. 'The process of philosophizing, to my mind, consists mainly in passing from those obvious, vague, ambiguous things, that we feel quite sure of, to something precise, clear, definite, which by reflection and analysis we find is involved in the vague thing that we start from, and is, so to speak, the real truth of which that vague thing is a sort of shadow", said Russell, in connection to his 'logical atomism'. But then, he was never really able to define a "logical atom" subsequently.
So - let's think about the definition of 'irony'......