While the althing (see above) was the closest organization the Icelandic Vikings had to America's federal government/court system/police, the thing was the closest approximation the Icelandic Vikings had to local government/court systems/police The thing was a gathering of representatives from the local area to vote on policy, hear complaints, settle disputes, and proclaim incorrigible individuals as outlaws (see above)
If you say that a person knows a thing or two about something or could teach someone a thing or two about it, you mean that they know a lot about it or are good at it. Patricia Hewitt knows a thing or two about how to be well-organised The peace movement has learnt a thing or two from Vietnam
A thing is a physical object that is considered as having no life of its own. It's not a thing, Beauchamp. It's a human being!
vagueness You can use thing to refer in a vague way to a situation, activity, or idea, especially when you want to suggest that it is not very important. I'm a bit unsettled tonight. This war thing's upsetting me
emphasis You can say that the first of two ideas, actions, or situations is one thing when you want to contrast it with a second idea, action, or situation and emphasize that the second one is much more difficult, important, or extreme. It was one thing to talk about leaving; it was another to physically walk out the door
If you say that something is the done thing, you mean it is the most socially acceptable way to behave. It was not the done thing. In those days the man was supposed to be the provider
Thing is used in lists and descriptions to give examples or to increase the range of what you are referring to. These are genetic disorders that only affect males normally. They are things like muscular dystrophy and haemophilia The Earth is made mainly of iron and silicon and things like that