Teacher: Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.
Teacher: Now, understand the problem? If you are still confused, see the following example:
How are i.e. and e.g. pronounced?
Solution: i.e. stands for id est (Latin), which means 'that is'. You use it to link in a deeper explanation about something. Pronounce it 'eye - ee'. e.g. stands for exempli gratia (also Latin), which means 'for example'. You use it to link in an example of a more generic term. Pronounce it 'ee - jee'
Reason: Perfect answer because it's consistent with context uses required information from the question to provide the detailed answer with an example.

Now, solve this instance: Possible Duplicate: How and why have some words changed to a complete opposite? I have noticed that: horrible means bad terrible means bad horrific means bad So why does terrific mean good?.
Student:
The meaning of terrific has actually changed over time. According to EtymOnline: 1660s, 'frightening,' from L. terrificus 'causing terror or fear,' from terrere 'fill with fear' (see terrible) + root of facere 'to make' (see factitious). Weakened sensed of 'very great, severe' (e.g. terrific headache) appeared 1809; colloquial sense of 'excellent' began 1888. So terrific started out on the same lines as horrific, but then gained a positive colloquial sense in the late 1800s. The phenomenon in which a previously bad word takes on a good connotation is discussed here, in which it is called amelioration. Amelioration (which has occurred for terrific, wicked, luxury) is a type of semantic change. While it is unclear what precisely happened to terrific, there are a few ways in which this change can occur: Linguistic forces Psychological forces Sociocultural forces Cultural/encyclopedic forces You can read more about it here. It has been suggested (though there is little proof) that terrific became 'good' because of an association with the popular media via King Kong. Other than this theory, though, it is clear that terrific underwent some kind of semantic change between the late 1800s and early 1900s. In 1930 Popular Science was still using the term to mean something 'frightening', and by the 1940s it was used mostly to mean 'good'.