The study of proper names or of terms used in a specialized field.
Okay--how is this different from jargon?
how is this different from jargon?
Onomastics (as its name implies) deals with proper names. Jargon is a specialize vocabulary use in a field. It may include some proper names, but also other non-name words.
all squares are rectangles, but not all rectangles are squares.
Jargon is applied to a technical or esoteric language used by a profession, trade, or cult.
Example: Educationese is the jargon of educational theorists.