'Eskimo' is an Athabascan Indian word meaning 'eaters of raw meat'. Most 'Eskimo' prefer their own word, 'Inuit', which means 'people' (note that it is a plural word so it's not correct to say 'Tom is an Inuit'; the singular is 'Inuk').
Many local dialects have variations referring to regional groupings (eg. 'Inuinait', 'Inuvialuit'). The 'it' ending is a plural ending.
The use of 'Inuit' is not entirely problem-free. There is no other word for 'people', so it's tough to say 'They are not Inuit'! In fact, in Inuktitut translations of the Bible, Jesus feeds 5000 Inuit!
Also, not all Eskimos are offended by the word 'Eskimo'. I lived in the western and central Arctic from 1984-91 and had to learn to speak Inuinaktun to do my job. Most local folks there were quite OK with the word 'Eskimo'. In the east, however, they considered it offensive and 'Inuit' was universal.
(No connection at all with the original thread; just trying to offer some accurate linguistic information!).