Definitions of synthetic:

• noun:   a compound made artificially by chemical reactions
• adjective:   of a proposition whose truth value is determined by observation or facts

  Example: "`all men are arrogant' is a synthetic proposition"

• adjective:   systematic combining of root and modifying elements into single words
• adjective:   involving or of the nature of synthesis (combining separate elements to form a coherent whole) as opposed to analysis

  Example: "Limnology is essentially a synthetic science composed of elements...that extend well beyond the limits of biology- P.S.Welch"

• adjective:   not genuine or natural

  Example: "Counterfeit rhetoric that flourishes when passions are synthetic- George Will"

• adjective:   artificial as if portrayed in a film
• adjective:   not of natural origin; prepared or made artificially

  Example: "Synthetic leather"