A category of options which includes complicated components and complex payoffs.  Its payoff or other key values often depend on outside factors which vary over time, such as exchange rate.  Because of their complexity, exotic options are often traded over the counter rather than through an exchange.  Asian-style options are one type of exotic options.  opposite of plain vanilla option.
Related information about exotic option:
- Exotic option - Wikipedia, the free encyclopedia
 In finance, an exotic option is a derivative which has features making it more   complex than commonly traded products (vanilla options); see Exotic derivatives.
 
- Exotic Option Definition | Investopedia
 An option that differs from common American or European options in terms of the   underlying asset or the calculation of how or when the investor receives a ...
 
- What's the difference between a regular option and an exotic option?
 Before learning about exotic options, you should have a fairly good   understanding of regular options. Both types of options share the idea of having.
 
- Exotic Option - Financial Dictionary - The Free Dictionary
 Exotic Option. Also found in: Wikipedia, 0.03 sec. Exotic option. Refers to options   that are more complex than simple put or call options. For example, a Caput is ...
 
- What is exotic option? definition and meaning
 Definition of exotic option: A category of options which includes complicated   components and complex payoffs. Its payoff or other key values often depend on ...
 
- Exotic Option Pricing and Advanced Levy Models (Wilmott ...
 Since around the turn of the millennium there has been a general acceptance   that one of the more practical improvements one may make in the light of the ...
 
- Exotic option: Definition from Answers.com
 option contracts that are variations on simple puts and calls or are different   products with optionality built into them.
 
- Wiley: Exotic Option Pricing and Advanced Lévy Models
 Since around the turn of the millennium there has been a general acceptance   that one of the more practical improvements one may make in the light of the ...