humour, wit, satire, sarcasm, invective, irony, cynicism, the sardonic.

So much has been written upon the nature of some of these words, and upon the distinctions between pairs or trios among them (wit and humour, sarcasm and irony and satite), that it would be both presumptuous and unnecessary to attempt a further disquisition. But a sort of tabular statement may be of service against some popular misconceptions. No definition of the words is offered, but for each its motive or aim, its province, its method or means, and its proper audience, are specified. The constant confusion between sarcasm, satire and irony, as well as that now less common between wit and humour, seems to justify this mechanical device of parallel classification; but it will be of use only to those who wish for help in determining which is the word that they really want.
Fowler's Modern English Usage
Motive or aim Province Method or means Audience
humour Discovery Human nature Observation The sympathetic
wit Throwing light Words and ideas Surprise The intelligent
satire Amendment Morals and manners Accentuation The self-satisfied
sarcasm Inflicting pain Faults and foibles Inversion Victim and bystander
invective Discredit Misconduct Direct statement The public
irony Exclusiveness Statement of facts Mystification An inner circle
cynicism Self-justification Morals Exposure of nakedness The respectable
the sardonic Self-relief Adversity Pessimism Self

irony, n.

1. A figure of speech in which the intended meaning is the opposite of that expressed by the words used.
2. figurative. A condition of affairs or events of a character opposite to what was, or might naturally be, expected; a contradictory outcome of events as if in mockery of the promise and fitness of things.
3. in etymological sense. Dissimulation, pretence; especially in reference to the dissimulation of ignorance practised by Socrates as a means of confuting an adversary (Socratic irony).
4. specifically in theatre. The incongruity created when the (tragic) significance of a character's speech or actions is revealed to the audience but unknown to the character concerned (dramatic irony).
The Oxford English Dictionary