The meaning of PACK is a bundle arranged for convenience in carrying especially on the back. How to use pack in a sentence. PACK definition: 1. to put something into a bag, box, etc.: 2. to put a material around something before putting it…. Learn more. 1. To place one's belongings in boxes or luggage for transporting or storing. 2. To be susceptible of compact storage: Dishes pack more easily than glasses. 3. To form lumps or masses; become compacted. You can refer to a group of people who go around together as a pack, especially when it is a large group that you feel threatened by. He thus avoided a pack of journalists eager to question him. Definition of pack verb in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more. a definite quantity or standard measure of something wrapped up or otherwise assembled for merchandising (sometimes used in combination): a pack of cigarettes; a six-pack of beer. Pack definition: The amount, as of food, that is processed and packaged at one time or in one season.