Some types of definition (and essays in which they are used)
Dictionary definition - use only sparingly and only as one of several other methods (Eighner, Alexander)
Narrative definition - something which is defined through a story told by a narrator. (Walker, Ascher)
Anecdote definition - told as a story about someone else, like the scientists Isaac Newton or Kepler (Bronowski)
Definition by allusion - usually relates only a part of a definition or is used to contrast. Allusion indicates a well known work or situation and 'instantly' defines - "foil" can be defined by allusion to Wil Smith in Men in Black. (Ascher)
Defiintion by parts - indicating the parts of an abstraction (Mernissi - the parts of a Harem)
Definition by function - defining "Democracy" by the events that occur around an election or the method used to pass a law.
Definition by what it is not - showing what 'solitude' is not, i.e. loneliness. (Ascher)
Definition by interaction - the archery student interacts with the bow and arrow and with his instructor and with his wife who is studying a similiar art. Via the interaction he learns the Zen of archery. (Highet)
Definition by synonyms - using a SERIES of synonyms to round out a definition (Alexander, Eighner)
Symbolic definition - using a symbol, like the 'world in an eye' to define (Walker)
Tone definition - how a word is used, tonally, defines its meaning (Naylor)
Definition by contrast - Contrasting concepts that are similar with the concept under definition (Ascher).
