A fascinating interview on RTE radio today with John Simpson, the former editor of the Oxford English Dictionary, describing how he essentially fell into lexicography, and the process of how words meet the etymological prerequisites for inclusion. If one is uninterested, you have no interest in a topic, but a disinterested person merely isn't concerned either way. Surprisingly, it appears that amadán, which would seem a fairly common word in Hiberno-English isn't formally instanced enough to feature in the OED.