The American Heritage® Dictionary of the English Language, 4th Edition
n. A small group of advanced students in a college or graduate school engaged in original research or intensive study under the guidance of a professor who meets regularly with them to discuss their reports and findings.
n. A course of study so pursued.
n. A scheduled meeting of such a group.
n. A meeting for an exchange of ideas; a conference.
n. A class held for advanced studies in which students meet regularly to discuss original research, under the guidance of a professor.
n. A meeting held for the exchange of useful information by members of a common business community.
the GNU version of the Collaborative International Dictionary of English
n. A group of students engaged, under the guidance of an instructor, in original research in a particular line of study, and in the exposition of the results by theses, lectures, etc.; -- formerly called also seminary, now seldom used in this sense.
The Century Dictionary and Cyclopedia
n. Same as seminary. 5.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. any meeting for an exchange of ideas
n. a course offered for a small group of advanced students
Word Usage
"The two hour seminar is a free two hour sales pitch for another seminar, which costs between $3,500 and $4,000."