The concept of allegory you are talking about is called personification and has been mainly used in literature in medieval times and the baroque.
There are other types of allegories, like in the Hebrew Bible, let's say Psalm 80, talking about the vine that stands for Israel. Things, as the vine, and actions can be allegorical.
In arts there are many allegorical pictures. A personification would be Justice as a blindfolded woman with scales.
Fables are a subcategory of allegories, as are parables. Both probably are characterized by shortness.
All three categories are forms of writing, art, or spoken utterance that encourage readers to look for meanings beyond what is said.
As for the difference between fable and parable: the fable, as the OP says, has animals, plants, or objects acting. It therefore has to anthropomorphize, while a parable draws its images from human interaction mostly.
Therefore a fable most the time is more schematic in build and easier to decipher. Parables often allow for different ways of deciphering. Looking at Kafka, Brecht, or biblical parables, it is clear that there is often a key, hint, or explanation needed to decipher the parable.
This might be because a fable describes something that is naturally not possible, as the actors are anthropomorphized, creating its moral effect using striking simplification, while the parable describes a naturally possible incident, allowing for more complexity due to acquaintance, creating its moral or parabolic effect through surprise. Fable and parable therefore have much in common and overlap greatly.
Defining the word "sarcasm" is fairly straightforward. It usually means the expression of a sentiment whose opposite is meant. For example:
Hooray! I have a headcold.
Irony, however, eludes a simple explanation, and there tend to be disagreements about its meaning between UK and US speakers. Irony is found in the contrast between expected, or ordinary, outcomes and what actually happens. The greater the distance, the greater the irony.
For example: In this video, the police officer is giving a lecture on firearms safety, and shoots himself in the leg: http://www.youtube.com/watch?v=am-Qdx6vky0
That's an example of situational irony. And note that irony need not be funny, although it often is.
Best Answer
inverse: opposite or contrary in position, direction, order, or effect
in mathematics - something obtained by inversion or something that can be applied to an element to produce its identity element
reverse: opposite primarily in direction
in law - reverse or annul
in printing - make print white in a block of solid color or half tone
in electronics - in the direction that does not allow significant current
in geology - denoting a fault or faulting in which a relative downward movement occurred in the strata situated on the underside of the fault plane
converse: corresponding yet opposing
in mathematics - a theorem whose hypothesis and conclusion are the conclusion and hypothesis of another
also a brand of shoe
transverse: situated across from something
obverse: the opposite or counterpart of something (particularly a truth)
in biology - narrower at the base or point of attachment than at the apex or top
from NOAD
Reverse is the only one I've commonly heard in casual speech and only referring to the direction of a car (in US... don't know about UK et al). Some could be used interchangeably, but it would be best to avoid it considering that each generally has a specific meaning in its context.