Real Dictionary

thing
Thing is often used after an adjective, where it would also be possible just to use the adjective. For example, you can say it's a different thing instead of it's different.
Thing is used in lists and descriptions to give examples or to increase the range of what you are referring to.
countable noun: You can use thing to refer to any object, feature, or event when you cannot, need not, or do not want to refer to it more precisely.
singular noun: Thing is often used instead of the pronouns 'anything,' or 'everything' in order to emphasize what you are saying.

thing in American English 1
any matter, circumstance, affair, or concern
noun: a material object without life or consciousness; an inanimate object

thing in American English 2
a Scandinavian legislative body
noun: a public meeting or assembly, esp. a legislative assembly or a court of law

thing in British English 1
noun: an object, fact, affair, circumstance, or concept considered as being a separate entity

thing in British English 2
noun: a law court or public assembly in the Scandinavian countries