where 
(wâr, hwâr)
(wâr, hwâr)adv.
1. At or in what place: Where is the elevator?
2. In what situation or position: Where would we be without your help?
3. From what place or source: Where did you get this idea?
4. To what situation; toward what end: Where is this argument leading?
conj.
1.
a. At, to, or in a place in which: He lives where the climate is mild. We should go where it is quieter.
b. At, to, or in a situation in which: I want to know where you expect the project to be in six months.
2.
a. At, to, or in any place in which; wherever: Sit where you like.
b. At, to, or in any situation in which; wherever: Keeping dangerous substances out of reach is important where children are concerned.
3. Whereas: That model has an attractive design, where this one is more dependable.
4. Usage Problem That: I read where they're closing down the paper mill.
pron.
1.
a. At, to, or in a place in which: She moved to a city where jobs were more plentiful.
b. What place, source, or cause: Where are you from?
c. The place or situation at, in, or to which: We're already three miles from where we left.
2. Usage Problem In which: Show me an example where increasing supply has actually increased demand.
n.
The place or occasion: We know the when but not the where of it.
[Middle English, from Old English hwǣr; see kwo- in the Appendix of Indo-European roots.]
Usage Note: When where is used to refer to a point of origin, the preposition from is required: Where did she come from? From where I sit, the situation looks bleak. When it is used to refer to a destination, the preposition to is generally superfluous: Where is she going (rather than Where is she going to)? The place where they are going is beautiful. When it is used to refer to the location of a person, event, or structure, the use of at is widely regarded as regional or colloquial: Where is the station (not Where is the station at)? · Where is also used to mean "in which" as in Show me an example where government intervention in the market has worked. The Usage Panel has mixed feelings about this. In our 2001 survey, 60 percent accepted the example just given, but only 44 percent accepted Sometimes the discussion degenerates into a situation where each person accuses the other of being illogical. These usages probably derive from the positional use of where in sentences like He went to the house where the money was kept and We hid the present in the closet where we hang our coats. These positional usages are standard, but in all of these instances, where can be safely and clearly replaced by in which. · Where is also used in instances where that might normally be expected, as in I don't see where they had much choice but to give up. The Usage Panel has less fondness for this usage. Only 30 percent of the Panel accepted this sentence in our 2001 survey. See Usage Note at why.