Definition of dinosaur Merriam-Webster's Online Dictionary Extinction Definition of dinosaur Merriam-Webster's Online Dictionary 3: one that is impractically large, out-of-date, or obsolete 3: one that is impractically large, out-of-date, or obsolete www.merriam-webster.com... http://www.merriam-webster.com/dictionary/dinosaur Definition of dinosaur Merriam-Webster's Online Dictionary dinosaur http://www.merriam-w...ionary/dinosaur